JP2005143410A5 - - Google Patents

Description

Paddy field machine

  The present invention relates to paddy field work machines such as a riding type rice transplanter and a riding type direct seeding machine.

  A riding-type rice transplanter, which is an example of a paddy field work machine, includes, for example, right and left front wheels (4 in FIGS. 1 and 4 of Patent Document 1), Provided with rear wheels (6 in FIGS. 1 and 4 of Patent Document 1), the right and left rear wheels are passed through right and left suspension mechanisms (9 in Patent Document 1, FIGS. 1, 3, and 4). There is something that was independently supported. Thereby, traveling stability is ensured by the right and left rear wheels moving up and down independently with traveling on the paddy field (cultivating board).

JP 2003-2078 A (FIGS. 1, 3 and 4)

When the right and left rear wheels are independently supported via the right and left suspension mechanisms as in the structure of Patent Document 1, the operating range of the right and left suspension mechanisms is limited. There is room for improvement in terms of running stability when the paddy field is located below the paddy surface and the front and rear wheels are in contact with the ground.
An object of the present invention is to improve running stability of a paddy field work machine when the right and left rear wheels are independently supported via right and left suspension mechanisms in the paddy field work machine.

[I]
(Constitution)
The first feature of the present invention includes right and left front wheels and right and left rear wheels, and includes right and left operating arms that can move up and down, and the right and left rear wheels are connected to the right and left wheels. The right and left operation arms are independently supported via a suspension mechanism. A linkage mechanism is provided that links the right and left operating arms together so that the right and left operating arms move simultaneously.
The second feature of the present invention resides in the following configuration in the paddy field working machine of the first feature of the present invention.
The linkage mechanism is configured so that the right and left operation arms move simultaneously on the lowering side of the rear wheel.

(Function)
According to the first and second features of the present invention, both the right and left rear wheels reach the large recess of the tiller, and the right and left suspension mechanisms attempt to lower both the right and left rear wheels. At this time, for example, even if the right operating arm is operated to the lower side of the rear wheel, the left operating arm is delayed to operate to the lower side of the rear wheel, and the aircraft is inclined to the left, The operating arm operates simultaneously on the lower side of the rear wheel. Thereby, for example, even if there is a large recess in the cultivator, the state in which the right and left rear wheels are separated from the cultivator is reduced, and the state in which the aircraft is inclined to the right or left is suppressed.

(The invention's effect)
According to the first and second features of the present invention, for example, even if there is a large recess in the cultivator, the state in which the right and left rear wheels are separated from the cultivator is reduced, and the aircraft tilts to the right or left. As a result, the running stability of paddy field machines could be improved.

[II]
(Constitution)
The third feature of the present invention resides in the following configuration in the paddy field working machine of the first or second feature of the present invention.
A right side clutch capable of transmitting and interrupting power to the right rear wheel; and a left side clutch capable of transmitting and interrupting power to the left rear wheel. When the right and left front wheels are steered to the straight drive position, the right and left side clutches are operated to the transmission state, and when the right and left front wheels are steered from the straight drive position to the right or left, the vehicle turns. The center side clutch is configured to be operated in a disconnected state.

(Function)
According to the third feature of the present invention, the “action” described in the preceding item [I] is provided in the same manner as the first or second feature of the present invention. In addition, the following “action” is provided. Yes.
According to the third aspect of the present invention, when the right and left front wheels are steered to the straight position, the right and left side clutches are operated in a transmission state, and power is transmitted to the right and left rear wheels. The When the right and left front wheels are steered to the right or left, the side clutch on the turning center side is operated in a disengaged state, and the rear wheel on the turning center side freely rotates (rear wheel outside the turning). Power is transmitted to). As a result, the rear wheel on the turn center side moves forward while appropriately rotating along with the turn, and the state where the work site is roughened by the rear wheel on the turn center side during turning is reduced.

When configured as described above, the right and left front wheels are steered to the right or left, the turning center side clutch is operated in a disengaged state, and the turning center side rear wheel is in a freely rotating state. Then, the suspension mechanism outside the turning and the operation arm outside the turning may be operated to the lower side of the rear wheel by the power that the rear wheels outside the turning are driven to rotate in the forward direction. There are times when it tries to incline to the turning center side.
In the third aspect of the present invention, if the linkage mechanism according to the first or second aspect of the invention is provided, the linkage arm is operated when the operation arm on the outer side of the turn is actuated to the lower side of the rear wheel as described above. Since the operation arm on the turning center side is also actuated to the lowering side of the rear wheel by the mechanism, the state where the rear wheel on the turning center side is separated from the cultivator is reduced, and the state where the aircraft is inclined toward the turning center side is suppressed. .

(The invention's effect)
According to the third feature of the present invention, the “effect of the invention” described in the preceding item [I] is provided in the same manner as the first or second feature of the present invention. In addition, the following “effect of the invention” is provided. Is provided.
According to the third feature of the present invention, when the right and left front wheels are steered to the right or left, the side clutch on the turning center side is operated in the disengaged state, and the rear wheel on the turning center side freely rotates. By being configured to be in a state, the state where the work area is roughened by the rear wheel on the turning center side during turning is reduced, and the turning performance of the paddy field work machine can be improved.

In the third feature of the present invention, if the linkage mechanism of the first or second feature of the present invention is provided, the right and left front wheels are steered to the right or left, and the side clutch on the turning center side is in the disconnected state. When the operation arm on the outer side of the turn is operated to the lowering side of the rear wheel, the operation arm on the turning center side is also operated to the lowering side of the rear wheel by the linkage mechanism, and the rear wheel on the turning center side is operated. The state in which the paddy field machine is turning away from the cultivator is reduced, and the state in which the machine body is inclined toward the turning center side is suppressed, so that it is possible to improve the running stability during turning of the paddy field work machine.

[III]
(Constitution)
A fourth feature of the present invention resides in the following configuration in any one of the paddy field working machines of the first to third features of the present invention.
Provided with a stabilizer that urges the right and left rear wheels in a direction that provides resistance to the difference in height between the right and left rear wheels and eliminates the difference in height between the right and left rear wheels. .

(Function)
According to the 4th characteristic of this invention, it is equipped with the "action" of previous clause [I] [II] similarly to any one of the 1st-3rd characteristics of this invention, and also in addition to this. It has “action” like
According to the fourth aspect of the present invention, the state in which the difference in height between the right and left rear wheels becomes unnecessarily large and the airframe tends to tilt can be suppressed by the stabilizer.

(The invention's effect)
According to the fourth aspect of the present invention, the “effect of the invention” described in the preceding paragraphs [I] and [II] is provided in the same manner as any one of the first to third aspects of the present invention. The following “effects of the invention” are provided.
According to the fourth aspect of the present invention, the difference between the heights of the right and left rear wheels becomes unnecessarily large, and the state in which the aircraft tends to incline is suppressed by the stabilizer. Was able to improve.

[IV]
(Constitution)
A fifth feature of the present invention resides in the following configuration in any one of the paddy field working machines of the first to fourth features of the present invention.
A working mechanism is supported at the rear of the machine body so as to be movable up and down, and an elevating mechanism for driving the working apparatus up and down is provided. The right and left rear wheels are actuated to the lower side in conjunction with the work mechanism being lifted by the lifting mechanism over a predetermined height from the surface.
The sixth feature of the present invention resides in the following configuration in the paddy field working machine of the fifth feature of the present invention.
By the lifting mechanism, the right and left operation arms are configured to be actuated to the lower side of the rear wheel.

(Function)
According to the fifth and sixth features of the present invention, the “action” described in the preceding paragraphs [I] to [III] is provided as in any one of the first to fourth features of the present invention. In addition, it has the following “actions”.
The paddy field machine generally moves forward by the driving force of the right and left rear wheels, so the front part of the machine body is lifted by the driving reaction force of the right and left rear wheels. Is supported, the state where the front part of the airframe is about to be lifted can be suppressed by grounding the work device. However, when the paddy field work machine completes one work process and reaches the shoreline, the work device may be driven to rise greatly from the surface, and the machine body may be turned at the shore to enter the next work process.
As a result, when the working device is driven to rise greatly from the surface when turning the aircraft as described above, the state where the working device tries to lift the front part of the aircraft disappears, so the right and left rear wheels Due to the driving reaction force, the front part of the aircraft is about to be lifted, and the ground pressure of the right and left front wheels is lowered, and the aircraft may not be able to turn smoothly.

According to the fifth and sixth features of the present invention, when the work device is driven to rise above a predetermined height by the lifting mechanism , the right and left rear wheels are actuated downward. As a result, the rear part of the fuselage is lifted and the center of gravity of the fuselage moves slightly forward, or the fuselage is lowered forward, and the state where the front part of the fuselage is about to be lifted by the working device is suppressed. Even if the front part of the fuselage is lifted by the driving reaction force of the right and left rear wheels, the right and left rear wheels are actuated to the lower side, so that the right and left rear wheels The state in which the front part of the airframe is lifted by the driving reaction force is suppressed, and the decrease in the ground pressure of the right and left front wheels is suppressed.

According to the fifth and sixth features of the present invention, as described above, when the working device is driven upward by the lifting mechanism beyond the predetermined height by the lifting mechanism, the right and left rear wheels are actuated downward . While the right and left rear wheels are moved downward , the ground pressure on the right and left rear wheels temporarily increases. Thus, according to the fifth and sixth features of the present invention, when the turning of the airframe is started while the working device is driven up by the lifting mechanism, the ground pressure of the right and left rear wheels is temporarily high. As a result, the driving forces of the right and left rear wheels are appropriately transmitted to the cultivator and the turning of the airframe is started smoothly.

According to the sixth aspect of the present invention, when the working device is driven to rise above a predetermined height by the lifting mechanism, the right and left operation arms are actuated to the lower side of the rear wheel by the lifting mechanism. The right and left rear wheels are actuated downward . Thus, according to the sixth feature of the present invention, the lifting mechanism is also used as a mechanism for operating the right and left rear wheels to the lowering side, and another mechanism for operating the right and left rear wheels to the lowering side . The mechanism becomes unnecessary (even if another mechanism for operating the right and left rear wheels to the lower side is provided, a small-scale one may be used).

(The invention's effect)
According to the fifth and sixth features of the present invention, as in any one of the first to fourth features of the present invention, the “effect of the invention” described in the preceding items [I] to [III] is provided. In addition to this, the following “effects of the invention” are provided.
According to the fifth and sixth features of the present invention, in the case where the working device is supported at the rear of the machine body so as to be movable up and down and the working device is driven to move up and down, the working device is raised from the surface by the lifting mechanism. When the vehicle is lifted beyond that, the right and left rear wheels can be actuated to the lower side, so that a decrease in the ground pressure of the right and left front wheels can be suppressed. It was possible to avoid the situation where the aircraft could not turn smoothly due to a decrease in the contact pressure of the front wheels, and the turning performance of the paddy field work machine could be improved.

According to the fifth and sixth features of the present invention, when the working device is lifted up beyond the predetermined height by the lifting mechanism and the right and left rear wheels are actuated downward , the right and left The ground pressure of the rear wheels will be temporarily increased, and the driving force of the right and left rear wheels will be properly transmitted to the cultivator, so that the aircraft can start turning smoothly. As a result, the turning performance of the paddy field machine could be improved.
According to the sixth feature of the present invention, there is no need for another mechanism for operating the right and left rear wheels to the lower side (even if another mechanism for operating the right and left rear wheels to the lower side is provided. Smaller size is better), which is advantageous in terms of simplified structure.

[1]
As shown in FIGS. 1 and 2, one top link 3 and two lower links 4 swing up and down at the rear of the aircraft supported by the right and left front wheels 1 and the right and left rear wheels 2. An example of a paddy field work machine is provided that includes a hydraulic cylinder 5 that is freely supported and that drives the top link 3 and the lower link 4 to move up and down. The seedling planting device 6 is supported at the rear of the top link 3 and the lower link 4. This is a riding type rice transplanter.

  As shown in FIGS. 1 and 2, the seedling planting device 6 is configured in a four-row planting type, and can be driven to rotate to two transmission cases 9 and to the right and left lateral sides of the rear portion of the transmission case 9. And a pair of planting arms 11 provided at both ends of the planting case 10, a grounding float 12, a seedling table 13, and the like. As a result, the planting case 10 is rotationally driven as the seedling platform 13 is driven back and forth to the left and right, and the planting arm 11 alternately takes out the seedlings from the lower part of the seedling platform 13 and the surface G To plant.

  As shown in FIGS. 1 and 2, a hopper 15 that stores fertilizer, a feeding portion 16, and a blower 17 are provided on the rear side of a driver's seat 14 provided in the airframe. A groover 18 is provided on the ground float 12, and a hose 19 is connected across the feeding portion 16 and the groover 18. As a result, the fertilizer is fed from the hopper 15 by a predetermined amount by the feeding unit 16 along with the seedling planting as described above, and the fertilizer is supplied to the groove producing device 18 through the hose 19 by the blower 17 blowing. Yes, fertilizer is supplied to the rice field G via the groove generator 18.

  As shown in FIGS. 3 and 5, right and left support frames 20 are fixed vertically on the rear of the aircraft, and a horizontal frame 21 is connected across the right and left support frames 20. The lower link 4 is supported so as to be swingable up and down around the horizontal axis P2 in the left-right direction of the machine body below the support frame 20. A support shaft 22 is installed over the right and left support frames 20, and a cylinder-side bracket 5a of the hydraulic cylinder 5 is supported so as to be swingable up and down around a horizontal axis P3 of the support shaft 22 in the horizontal direction of the body. The piston rod of the hydraulic cylinder 5 is connected to the tip of the lower link 4. On the outside of the cylinder side bracket 5a of the hydraulic cylinder 5, the top link 3 is supported so as to be swingable up and down around the horizontal axis P3. Thus, when the hydraulic cylinder 5 is contracted, the top link 3 and the lower link 4 are driven to swing upward, and the seedling planting device 6 is driven upward. When the hydraulic cylinder 5 is extended, the top link 3 and the lower link 4 are driven to swing downward, and the seedling planting device 6 is driven downward.

  As shown in FIGS. 1 and 2, a steering handle 38 for steering the right and left front wheels 1 is provided in front of the driver seat 14, and an elevating lever 39 is provided on the right side portion of the steering handle 38. Is provided. The raising / lowering lever 39 can be freely operated in the ascending position, neutral position, descending position and planting position, and the ascending position, neutral position, descending position and planting position are arranged in this order from the rear side to the front side. . When the elevating lever 39 is operated to the raised position, a planting clutch (not shown) that transmits power to the seedling planting device 6 is operated in a disconnected state, and the seedling planting device 6 is driven up by the hydraulic cylinder 5. . When the elevating lever 39 is operated to the neutral position, the planting clutch is operated in the disengaged state, and the hydraulic cylinder 5 is stopped. When the elevating lever 39 is operated to the lowered position, the planting clutch is operated in the disengaged state, and the seedling planting device 6 is driven downward by the hydraulic cylinder 5. When the elevating lever 39 is operated to the planting position, the planting clutch is operated in the transmission state, and the seedling planting device 6 is automatically driven up and down by the hydraulic cylinder 5 so as to be maintained at the set height from the rice field G. The

[2]
Next, support structures for the right and left front wheels 1 and the right and left rear wheels 2 will be described.
As shown in FIGS. 1 and 11, a narrow mission case 40 is provided in the front-rear direction of the fuselage in the center of the left and right sides of the fuselage, and right and left front axle cases 41 are extended from the front of the mission case 40, A front wheel support case 7 that supports the right and left front wheels 1 is supported by the end portions of the right and left front axle cases 41 so as to be steerable. The right and left support cases 8 are independently swingably supported up and down around the horizontal axis P1 in the left-right direction of the machine body at the rear of the mission case 40, and the right and left support cases 8 extend rearward. The right and left rear wheels 2 are supported at the rear of the right and left support cases 8.

  As shown in FIGS. 5 and 11, brackets 8 b are fixed to the inner portions of the right and left support cases 8, and the thin and long leaf spring members 42 extend over the brackets 8 b of the right and left support cases 8. Are connected. As a result, when a difference in height occurs between the right and left support cases 8 (right and left rear wheels 2), the urging force of the leaf spring member 42 causes the right and left support cases 8 (right and left rear wheels). 2) acts in the direction of eliminating the height difference. This state is suppressed by the leaf spring member 42 even if the right and left support cases 8 try to be separated from each other right and left laterally outward.

  As shown in FIGS. 3 and 5, the support shaft 23 is fixed to the right and left support frames 20, and the right and left operation arms 24 are vertically moved around the horizontal axis P <b> 4 in the longitudinal direction of the body of the support shaft 23. It is swingably supported. As shown in FIGS. 10 (a) and 10 (b), the right and left operation arms 24 are formed in a balance shape by bending a plate material, and a bearing portion 24f near the center into which the support shaft 23 is inserted, one end. The concave spherical surface portion 24b provided in the portion, the opening portion 24c provided in the spherical surface portion 24b, the long first arm portion 24d and the short second arm portion 24e provided in the other end portion, the first and second arms. The pin 24a is fixed over the portions 24d and 24e. In the state where the pin 24a is not fixed, the right and left operation arms 24 are exactly the same, and are set to the right and left operation arms 24 by setting them in opposite directions.

  As shown in FIGS. 3 and 5, in the state where the right and left operation arms 24 are swingably supported up and down around the horizontal axis P4, arc-shaped long holes 21a provided in the horizontal frame 21 are provided. The pins 24a of the right and left operation arms 24 are inserted into the right and left operation arms 24, and the swing range of the right and left operation arms 24 is restricted by the long holes 21a of the horizontal frame 21. Normally, as shown in FIGS. 3 and 5, the pin 24a of the right and left operation arms 24 is located at the lower end of the long hole 21a of the horizontal frame 21, and the first arm portion 24d of the right operation arm 24 is The pin 24a of the left operation arm 24 is in contact from above, and the first arm portion 24d of the left operation arm 24 is in contact with the pin 24a of the right operation arm 24 from above.

  As shown in FIGS. 3 and 5, right and left suspension mechanisms 25 are connected across one end of the right and left operation arms 24 and the right and left support cases 8. As shown in FIG. 5, a bracket 26 is supported swingably back and forth around the horizontal axis P5 in the left-right direction of the body of the bracket 8a fixed to the right and left support cases 8, and a pipe 27 is supported on the bracket 26. The eight soft rubber blocks 28 are externally fitted to the pipe 27. A hard resin receiving member 29 is externally fitted to the rubber block 28 and the pipe 27 at the upper end, and a soft rubber cover 30 is attached between the bracket 26 and the receiving member 29. The right and left suspension mechanisms 25 are configured as described above, and the suspension function is obtained by the rubber block 28.

  As shown in FIG. 5, in the right and left suspension mechanisms 25, the upper portion of the receiving member 29 is configured as a convex spherical portion 29 a, and the spherical portion 29 a of the receiving member 29 is formed by the right and left operation arms 24. The bolt 31 (thinner than the inner diameter of the opening 24c of the right and left operation arms 24) passes through the opening 24c of the right and left operation arms 24 and the receiving member 29. Are attached to the pipe 27.

  3 and 5, the pin 24a of the right and left operation arms 24 is positioned at the lower end of the long hole 21a of the horizontal frame 21, and the first arm portion 24d of the right operation arm 24 is operated to the left. The arm 24 is in contact with the pin 24a from above, and the first arm portion 24d of the left operation arm 24 is in contact with the pin 24a of the right operation arm 24 from above. 8 (right and left rear wheels 2) is in a normal state. When working in paddy fields or traveling on the road, the right and left support cases 8 (right and left rear wheels 2) swing up and down independently according to the unevenness, and the right and left suspension mechanisms 25 cause a shock. Absorbed (the pins 24a of the right and left operating arms 24 are positioned at the lower ends of the long holes 21a of the horizontal frame 21, and the right and left operating arms 24 are stopped in the state shown in FIG. 5).

  In this case, as shown in FIG. 5, even if the right and left suspension mechanisms 25 are inclined with respect to the right and left operation arms 24, the spherical surface portion 29a of the receiving member 29 and the spherical surfaces of the right and left operation arms 24 are provided. The portion 24 b absorbs the inclination of the right and left suspension mechanisms 25 with respect to the right and left operation arms 24, and the spherical portion 29 a of the receiving member 29 is converted by the bolt 31 into the spherical portion 24 b of the right and left operation arms 24. There will be no departure.

  In the state shown in FIGS. 3 and 5, for example, when the right support case 8 (the right rear wheel 2) is lowered and the right operation arm 24 swings around the horizontal axis P4 in the clockwise direction in FIG. The first arm portion 24d of the left operation arm 24 is pushed up from below by the pin 24a of the right operation arm 24, and the left operation arm 24 swings around the horizontal axis P4 in the counterclockwise direction in FIG. Move. As a result, the left support case 8 (the left rear wheel 2) is lowered via the left operation arm 24 and the left suspension mechanism 25.

[3]
Next, the transmission structure to the right and left front wheels 1 and the right and left rear wheels 2 will be described.
As shown in FIG. 11, a hydrostatic continuously variable transmission 43 is connected to the front part of the transmission case 40, and the power of the engine 44 supported on the front part of the airframe is hydrostatically continuously variable via a transmission belt 45. It is transmitted to the transmission 43. The power of the hydrostatic continuously variable transmission 43 is a gear transmission type auxiliary transmission (not shown), a front wheel differential device (not shown), right and left front axle cases provided inside the transmission case 40. 41 is transmitted to the right and left front wheels 1 via a transmission shaft (not shown) installed in 41.

  As shown in FIG. 11, right and left transmission shafts 46 are concentric and relatively rotatable over the rear portion of the mission case 40, the right and left support cases 8, and the right and left transmission shafts 46 are connected to each other. Between the sprocket 47 and the right and left transmission shafts 46, a right and left side clutch 49 is provided. Is provided. The right and left side clutches 49 are configured as a multi-plate friction type and are urged to a transmission state by a spring (not shown). As a result, the power of the auxiliary transmission is transmitted to the transmission chain 48, the sprocket 47, the right and left side clutch 49 (transmission state), the right and left transmission shafts 46, and the right and left support cases 8. Is transmitted to the right and left rear wheels 2.

  As shown in FIG. 11, a rack gear 51 is arranged in parallel to the right and left front axle cases 41 at the lower part of the front portion of the transmission case 40, and a tie rod 52 is connected across the rack gear 51 and the front wheel support case 7. Has been. The steering handle 38 and the rack gear 51 are linked so that the rack gear 51 is slid in parallel with the right and left front axle cases 41 by the steering handle 38, and the right and left front wheels 1 are operated by the steering handle 38. Can be operated in the opposite direction.

  As shown in FIG. 11, the linkage rod 54 is connected across the operation portion 53 that operates the right and left side clutch 49 in the disengaged state and the front wheel support case 7. As a result, when the right and left front wheels 1 are steered within the range of the rectilinear position, the set angle from the rectilinear position to the right and the set angle from the rectilinear position to the left, the right and left side clutches 49 are in a transmission state. , Power is transmitted to the right and left front wheels 1 and the right and left rear wheels 2. When the right and left front wheels 1 are steered to the right or left beyond the right or left set angle, the side clutch 49 on the turning center side is operated to be disconnected by pulling the linkage rod 54, and the turning center is turned on. The side rear wheel 2 is in a freely rotating state (power is transmitted to the right and left front wheels 1 and the rear wheel 2 on the outside of the turn).

[4]
Next, when the seedling planting device 6 is driven upward from the surface G by a hydraulic cylinder 5 beyond a predetermined height, the right and left support cases 8 (right and left rear wheels 2) are driven downward. Will be described.
As shown in FIGS. 3 and 5, an H-shaped switching member 32 is supported around the horizontal axis P <b> 6 of the top link 3 in the left-right direction of the machine body so as to be swingable back and forth. A roller 33 is rotatably supported. A U-shaped operation member 34 is supported around the horizontal axis P6 so as to be swingable back and forth in front view, and a spring 35 having a toggle function is connected across the switching member 32 and the operation member 34. An operation lever 36 is swingably supported back and forth around a horizontal axis P7 in the left-right direction of the machine body of the top link 3, and a linkage rod 37 is connected across the operation member 34 and the operation lever 36.

  The state shown in FIGS. 3 and 5 is a state in which the seedling planting device 6 is driven downward by the hydraulic cylinder 5 to the surface G, and the right and left support cases 8 (right and left rear wheels 2) are in a normal state. It is. When the operation lever 36 is operated to the operating position in the state shown in FIGS. 3 and 5, the operation member 34 is swung forward, the switching member 32 is swung forward by the spring 35, and the roller 33 is moved to the right and left. It enters the lower side of the pin 24a of the left operating arm 24.

  3 and FIG. 5, when the raising / lowering lever 39 is operated to the raised position, and the seedling planting device 6 is driven to rise from the field surface G beyond the predetermined height by the hydraulic cylinder 5, 4 and FIG. 6, the right and left left and right operating arms 24 are lifted upward so that the roller 33 contacts the pins 24 a of the right and left operating arms 24. The operating arm 24 swings around the horizontal axis P4, the right and left suspension mechanisms 25 are pushed down by the right and left operating arms 24, and the right and left support cases 8 (the right and left rear wheels 2). Is lowered, the rear part of the aircraft is lifted, and the aircraft is lowered forward.

  Next, when the raising / lowering lever 39 is operated to the lowered position and the seedling planting device 6 is driven downward by the hydraulic cylinder 5, the roller 33 moves downward and the right and left support cases are lowered while the rear part of the machine body is lowered. 8 (right and left rear wheels 2) are driven upward, and the right and left operation arms 24 swing around the horizontal axis P4 so that the pins 24a of the right and left operation arms 24 move downward. Thus, the right and left support cases 8 (right and left rear wheels 2) shown in FIGS. 3 and 5 return to the normal state.

  As shown in FIGS. 3 and 5, the right and left support cases 8 (right and left rear wheels 2) are in a normal state in a state where the seedling planting device 6 is driven down to the surface G by the hydraulic cylinder 5. 7, when the operation lever 36 is operated to the release position, the operation member 34 is swung back, the switching member 32 is swung back by the spring 35, and the roller 33 is moved to the right and left. The operation arm 24 is moved backward from the lower side of the pin 24a. As a result, even if the lifting lever 39 is operated to the raised position and the seedling planting device 6 is driven upward from the field G by the hydraulic cylinder 5, the roller 33 moves to the right and left operating arms 24. The right and left support cases 8 (the right and left rear wheels 2) are not driven downwardly (see the two-dot chain line in FIG. 7).

[5]
As shown in FIG. 8 (a), with the operation lever 36 operated to the operating position, the lifting lever 39 is operated to the raised position, and the seedling planting device 6 is moved from the field surface G to a predetermined height by the hydraulic cylinder 5. And the right and left support cases 8 (right and left rear wheels 2) are driven to move downward, as shown in FIG. The operating member 34 is swung rearward and the spring 35 moves rearward beyond the horizontal axis P6, but the roller 33 is pressed by the pins 24a of the right and left operating arms 24. The switching member 32 is not swung backward.

  Next, the raising / lowering lever 39 is operated to the lowered position from the state shown in FIG. 8 (b), and the seedling planting device 6 is driven downward by the hydraulic cylinder 5, and the right and left support cases 8 (right and left rear case) When the wheel 2) returns to the normal state, as shown in FIG. 8C, the roller 33 moves downward from the pins 24a of the right and left operating arms 24, so that the switching member 32 is moved backward by the spring 35. As a result of the swinging operation, the roller 33 moves backward from the lower side of the pin 24a of the right and left operation arms 24. Therefore, even if the raising / lowering lever 39 is operated to the ascending position after this and the seedling planting device 6 is driven upward from the field G by the hydraulic cylinder 5, the roller 33 remains on the right and left operating arms. Thus, the right and left support cases 8 (the right and left rear wheels 2) are not driven downward (see the state of FIG. 9 (A)).

  As shown in FIG. 9 (a), with the operation lever 36 operated to the release position, the lifting lever 39 is operated to the raised position, and the seedling planting device 6 is moved from the rice field G to a predetermined height by the hydraulic cylinder 5. In the state where the right and left support cases 8 (the right and left rear wheels 2) are not driven downward, the operation lever 36 is operated as shown in FIG. When operated to the position, the operation member 34 is swung forward, and the spring 35 moves forward beyond the horizontal axis P6, but the roller 33 contacts the right and left operation arms 24. Therefore, the switching member 32 is not operated to swing forward.

  Next, the raising / lowering lever 39 is operated to the lowered position from the state shown in FIG. 9 (b), and the seedling planting device 6 is driven downward by the hydraulic cylinder 5, so that the right and left support cases 8 (the right and left rear cases) When the wheel 2) returns to the normal state, as shown in FIG. 9C, the roller 33 moves downward from the right and left operation arms 24, so that the switching member 32 is swung forward by the spring 35. Then, the roller 33 enters the lower side of the pin 24a of the right and left operation arms 24. Therefore, after that, when the lifting lever 39 is operated to the ascending position and the seedling planting device 6 is driven upward from the surface G by the hydraulic cylinder 5, the roller 33 moves to the right and left operating arms. The right and left support cases 8 (the right and left rear wheels 2) are driven downward by contacting the 24 pins 24a (see the state of FIG. 8A).

[First Alternative Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention], when the right and left operation arms 24 shown in FIGS. 3 and 5 are abolished and the structure described in the preceding paragraphs [4] and [5] is abolished, FIG. 12 may be configured.
As shown in FIG. 12, the support frame 55 is fixed across the right and left support frames 20, and the right and left suspension mechanisms 56 extend across the ends of the support frame 55 and the right and left support cases 8. Is connected. An L-shaped rod member 57 is supported swingably back and forth around the horizontal axis P5 in the left-right direction of the body of the bracket 8a fixed to the right and left support cases 8, and the rod member 57 is supported by the support frame 55. A bolt 58 is attached to the upper end of the rod member 57 so as to be slidable at the end. Three soft rubber blocks 28 are fitted on the rod member 57, and the flange portion 57 a is fixed to the rod member 57. The right and left suspension mechanisms 56 are configured as described above, and the suspension function is obtained by the rubber block 28.

  As shown in FIG. 12, brackets 8 c that are U-shaped in plan view are fixed to the inner portions of the right and left support cases 8, and the rod members 59 extend across the brackets 8 c of the right and left support cases 8. Is connected. The rod member 59 is connected to the brackets 8c of the right and left support cases 8 so as to be swingable up and down, and the rod member 59 does not expand and contract. Accordingly, the difference in height between the right and left support cases 8 (right and left rear wheels 2) is allowed within a predetermined range by the rod member 59, and the right and left support cases 8 are allowed to move to the right and left. This state is suppressed by the rod member 59 even if they are separated from each other laterally outward.

[Second Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention], the right and left operation arms 24 shown in FIGS. 3 and 5 are not arranged around the horizontal axis P4 in the longitudinal direction of the aircraft, but in the horizontal axis ( (Not shown) may be configured to swing up and down.
The present invention can be applied not only to a riding type rice transplanter, but also to a paddy field working machine that supports a direct sowing apparatus in the rear part of the machine body so as to be movable up and down, and a paddy field work machine that supports a rotary rotary in the rear part of the machine body so as to be movable up and down.

Overall side view of riding rice transplanter Overall plan view of riding rice transplanter The state in which the right and left support cases (right and left rear wheels) are in the normal state when the seedling planting device is driven down to the paddy field by the hydraulic cylinder while the operation lever is operated to the operating position. Side view With the operating lever in the operating position, the seedling planting device is driven to rise above the predetermined height by the hydraulic cylinder, and the right and left support cases (right and left rear wheels) are driven downward. Side view showing the condition Rear view of the vicinity of the right and left operation arms in a state where the seedling planting device is driven down to the paddy field by the hydraulic cylinder while the operation lever is operated to the operating position. Rear view of the vicinity of the right and left operating arms in a state where the seedling planting device has been driven to rise above a predetermined height by the hydraulic cylinder with the operating lever in the operating position. The state in which the right and left support cases (right and left rear wheels) are in the normal state when the seedling planting device is driven down to the paddy field by the hydraulic cylinder while the operation lever is operated to the release position. Side view With the operating lever in the operating position, the seedling planting device was driven up by the hydraulic cylinder over a predetermined height from the surface, and the right and left support cases (right and left rear wheels) were driven down. Schematic side view showing the state in which the operating lever is operated to the release position in the state With the operating lever operated to the release position, the seedling planting device is driven up by the hydraulic cylinder beyond the predetermined height from the surface, and the right and left support cases (right and left rear wheels) are in the normal state. Schematic side view showing the state where the operating lever is operated to the operating position in the Rear view and plan view of right and left operation arms Schematic plan view showing the transmission structure to the right and left front wheels and the right and left rear wheels Longitudinal rear view of the vicinity of the right and left suspension mechanisms in the first alternative embodiment of the invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front wheel 2 Rear wheel 5 Lifting mechanism 6 Working device 24 Operation arm
24a, 24d Linkage mechanism 25 Suspension mechanism 42 Stabilizer 49 Side clutch G Tabu

Claims (6)

Provided with right and left front wheels and right and left rear wheels, with right and left operating arms that can move up and down, and right and left rear wheels independently through right and left suspension mechanisms And supporting it on the left operating arm,
A paddy field work machine provided with a linkage mechanism that links the right and left operation arms to each other so that the right and left operation arms move simultaneously . The paddy field work machine according to claim 1 , wherein the linkage mechanism is configured such that the right and left operation arms move simultaneously on the lowering side of the rear wheel . A right side clutch capable of transmitting and interrupting power to the right rear wheel, and a left side clutch capable of transmitting and interrupting power to the left rear wheel;
When the right and left front wheels are steered to the straight drive position, the right and left side clutches are operated to the transmission state, and when the right and left front wheels are steered from the straight drive position to the right or left, The paddy field work machine according to claim 1 or 2, wherein the side clutch on the turning center side is configured to be operated in a disengaged state.   Provided with a stabilizer that urges the right and left rear wheels in a direction that resists the difference in height between the right and left rear wheels and eliminates the difference in height between the right and left rear wheels The paddy field machine according to any one of claims 1 to 3. A working device is supported at the rear part of the machine body so as to be movable up and down, and includes a lifting mechanism that drives the working device up and down,
5. The right and left rear wheels are configured to be actuated to the lower side in conjunction with the working device being lifted and driven above the predetermined height by the lifting mechanism. The paddy field machine as described in any one of them. The paddy field work machine according to claim 5, wherein the right and left operation arms are actuated to the lowering side of the rear wheel by the lifting mechanism.