JP2012055184A - Paddy field working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paddy field working machine capable of preventing muddy water in a field from being gushed away in a large quantity outward from both right and left sides of a working device.SOLUTION: A ground levelling device is disposed between a travelling machine body and the working device. The ground-levelling device includes ground-levelling rotators 62A and 62B to be driven and rotated around a horizontal axis, and a mud cover 66 for preventing muddy water from scattering onto the working device. In the ground-levelling device 53, the large-diameter ground-levelling rotator 62A and small-diameter ground-levelling rotator 62B have different outer diameters from each other, and are disposed in such a state that the rotators are driven and rotated around the same horizontal axis. A small-diameter cover portion 66B of the mud cover 66 is disposed in such a state that the rear end of the portion is located on the machine body front side from the rear end of a large-diameter cover portion 66A, and a muddy water passing space S2 is formed between the small-diameter cover portion 66B and the large-diameter cover portion 66A.

Description

  According to the present invention, a working device is provided at a rear portion of the traveling machine body so as to be movable up and down by a raising and lowering driving means, and a ground leveling device is provided between the traveling machine body and the working device, and the leveling device is arranged around a horizontal axis. It is related with the paddy field machine comprised including the rotary body for leveling driven by rotation, and the mudguard cover which prevents that muddy water splashes in the said working device.

  Conventionally, in a riding type rice transplanter that is an example of a paddy field work machine, as disclosed in Patent Document 1, the leveling device has the same outer diameter over substantially the entire leveling work area along the horizontal width direction of the machine body. A mudguard cover was provided with a rotating body, and the mudguard cover was formed in a continuous plate shape over the entire width of the leveling device in the width direction of the machine body.

  By the way, in patent document 1, it has a large-diameter leveling rotary body and a small-diameter leveling rotary body having different outer diameters as the leveling device, and a sensor is included in the leveling work area along the horizontal direction of the machine body. Although a configuration including a small-diameter rotator for ground leveling in a region corresponding to the front side of the float body is also described, in this configuration as well, the mudguard cover is in the form of a plate that is continuously connected over the entire width of the leveling device in the body width direction. Each of the plurality of grounding floats is formed so that the position of the front end portion is the same in the longitudinal direction of the body.

JP 2009-207434 A [Refer to paragraphs (0031) and (0087), FIGS. 2 to 4]

  In the above conventional configuration, the leveling device is configured to include a leveling rotating body having the same outer diameter over the entire leveling work area along the body width direction, in the entire leveling work area along the body width direction, Although it is possible to satisfactorily perform leveling on the surface of the field (for example, if the field has a lot of water and is soft), the leveling device causes a large amount of soft mud in the field to be swept away from the left and right sides of the leveling work area. May end up.

  Therefore, in Patent Document 1, as described above, as a leveling device, a large-diameter leveling rotary body and a small-diameter leveling rotary body having different outer diameter dimensions are provided, and the large-diameter across the entire width direction of the machine body. It has been proposed to reduce the amount of muddy water that is forced to the outer side in the lateral direction of the machine body as compared with the one provided with a leveling rotator.

  However, in the conventional configuration described in Patent Document 1, the mudguard cover is formed in a plate shape that is continuously connected over the entire width of the leveling device in the width direction of the machine body even if it includes a small-diameter rotating body for leveling. For this reason, the mudguard cover may cause a large amount of soft mud in the field to be swept away from the left and right sides of the leveling work area.

Then, for example, in the case of a riding type rice transplanter, there is a disadvantage that the muddy water that is washed away in a large amount outward in the lateral direction of the machine body pushes down the already-planted seedlings already planted on the rice field in the previous work process.
In addition, when a large amount of muddy water is washed away outward in the lateral direction of the machine body, for example, a grounding float located on the rear side in the traveling direction of the leveling device is used to detect the height of the work device with respect to the surface. If the sensor float is configured to function as a sensor float and is controlled to move up and down so as to maintain the work device at the set height, the sensor float is located outward in the lateral direction in the body width. The muddy water is pushed away, and the surface height is lower than the other areas on the paddy surface, and the detection height of the sensor float is higher than the appropriate value corresponding to the surface height in the other areas on the paddy surface. There is a possibility that the lowering value becomes lower and the height of the working device to the ground is not an appropriate height, so that the lifting control cannot be performed satisfactorily.

  An object of the present invention is to provide a paddy field work machine capable of avoiding a large amount of muddy water in a farm field being swept away from the left and right sides of the work device.

The paddy field work machine according to the present invention is provided with a work device that can be lifted and lowered freely by a lift drive means at the rear part of the traveling machine body, and a ground leveling device is provided between the traveling machine body and the work device,
The leveling device is configured to include a leveling rotator that is driven to rotate around a horizontal axis, and a mudguard cover that prevents mud from splashing on the working device,
The first characteristic configuration is
The leveling device comprises a large-diameter leveling rotator and a small-diameter leveling rotator having different outer diameters in a state of being driven and rotated around the same horizontal axis,
In the mudguard cover, the small-diameter cover portion corresponding to the small-diameter leveling rotator has a rear end position that is larger than the rear-end position of the large-diameter cover portion corresponding to the large-diameter leveling rotator. It is provided in a state of being positioned on the front side of the machine body, and a muddy water passage gap is formed between the small diameter cover portion and the large diameter cover portion.

  According to the first characteristic configuration, the leveling device includes a large-diameter leveling rotator and a small-diameter leveling rotator having different outer diameters in a state of drivingly rotating around the same horizontal axis. Therefore, even if the muddy water on the surface is swept to the left and right sides of the large-diameter leveling rotator by the leveling action of the large-diameter leveling rotator, the small-diameter leveling rotator is mud-pushing. The muddy water swept away by the small-diameter leveling rotary body out of the muddy water swept away by the large-diameter leveling rotary body can be flow-guided to the rear side in the aircraft traveling direction.

  In addition, the muddy water that is guided to flow backward in the direction of travel from the location where the small-diameter rotator is present is received by the small-diameter cover part, and the small-diameter cover part is located outward on both sides in the body width direction. The muddy water that is washed away is received by the large-diameter cover portion located on the rear side of the machine body from the small-diameter cover portion, and is formed between the small-diameter cover portion and the large-diameter cover portion. Through the gap for passing muddy water, it can be flow-guided to the rear side in the traveling direction, and the amount of muddy water pushed away to the outer side in the machine width direction of the leveling device can be reduced.

  Accordingly, it has become possible to provide a paddy field work machine capable of avoiding a large amount of muddy water on the paddy surface being washed away on the outer side in the machine width direction of the leveling device.

  The second characteristic configuration of the present invention is that, in addition to the first characteristic configuration, the small-diameter cover portion and the large-diameter cover portion of the mudguard cover are configured by a split-type cover.

  According to the second characteristic configuration, the small-diameter cover portion and the large-diameter cover portion are constituted by a split-type cover, so that a gap for passing muddy water between the small-diameter cover portion and the large-diameter cover portion is used. It is easy to flow and guide the muddy water to the rear side in the traveling direction, and it has a small diameter compared to a large cover with a small diameter cover part and a large diameter cover part connected in series. Since the cover portion for large size and the cover portion for large diameter are each a small member, there is also an advantage that assembly is easy.

  In the third feature configuration of the present invention, in addition to the first feature configuration or the second feature configuration, a gap for passing muddy water is formed between the large-diameter leveling rotator and the small-diameter leveling rotator. There is in point.

  According to the third characteristic configuration, among the muddy water that is swept to the left and right sides of the large-diameter leveling rotator, the muddy water swept between the large-diameter leveling rotator and the small-diameter leveling rotator is: It can be guided to flow backward in the advancing direction of the airframe through the muddy water passage gap formed between the large-diameter leveling rotator and the small-diameter leveling rotator. The amount of muddy water that is washed away to the side can be more accurately reduced.

In addition to any of the first feature configuration to the third feature configuration, the fourth feature configuration of the present invention,
Any one of a plurality of grounding floats provided in the working device is configured as a sensor float that swings up and down around the rear horizontal axis while following the grounding and detects the ground height of the working device,
Elevation control means for controlling the elevating drive means to maintain the height of the working device relative to the surface based on the vertical swing of the sensor float at a set value is provided,
Of the leveling work area along the horizontal width direction of the machine body, the area corresponding to the front side of the machine body of the sensor float is provided with the rotating body for leveling the small diameter,
The sensor float is provided in a state in which the position of the front end portion thereof is positioned on the front side of the body relative to the position of the front end portion of the other grounding float.

  According to the fourth characteristic configuration, the elevation control means controls the elevation drive means so as to maintain the height of the working device with respect to the surface based on the vertical swing of the sensor float, but the front side of the sensor float body In the area corresponding to, a small-diameter rotator for leveling is provided, so in the front side of the sensor float, the muddy water on the surface is less likely to flow sideways, and the height difference with other areas on the surface is reduced. The error in detecting the height of the sensor float can be reduced.

  In addition, since the position of the front end of the sensor float is located on the front side of the fuselage relative to the position of the front end of the other grounding float, the grounding action length from the rear horizontal axis position to the front end position of the grounding action point becomes longer. Therefore, the detection accuracy of the sensor float is improved accordingly.

  Therefore, when performing the lifting control based on the vertical swing of the sensor float, it is possible to accurately detect the height of the working device with respect to the ground and maintain the height of the working device with respect to the surface level at a set value. The lifting drive means can be controlled.

  According to a fifth characteristic configuration of the present invention, in addition to any one of the first characteristic configuration to the fourth characteristic configuration, the small-diameter leveling rotator is positioned on a center side in the lateral direction of the fuselage, and the large-diameter leveling rotation It exists in the point arrange | positioned in the state which a body is located in the right-and-left both sides of the said small diameter rotary body for leveling.

According to the fifth characteristic configuration, the muddy water on the paddy surface is less likely to be swept to the left and right sides at the central side in the width direction of the airframe where the small-diameter leveling rotator is provided. Even if muddy water may be swept away by the rotating body, there is a small-diameter rotator on the center side in the width direction of the aircraft. The muddy water swept away by the air is guided to flow backward in the aircraft traveling direction.
Therefore, it is possible to effectively avoid a large amount of mud on the surface of the leveling device being pushed outward in the lateral direction of the machine body.

  In a sixth feature configuration of the present invention, in addition to any one of the first feature configuration to the fifth feature configuration, the leveling device is supported by the work device by a support portion, and overlaps the support portion in plan view. In addition, a leveling tool for leveling the field is provided.

According to the sixth characteristic configuration, since the leveling rotator is not provided at the place where the support unit for supporting the leveling device to the work device is present, the leveling action by the leveling rotator can be exhibited. Therefore, it is impossible to level the land surface.
Therefore, by providing a leveling tool that performs leveling on the surface in a state of overlapping with the support part in plan view, avoiding the occurrence of a non-leveling area where leveling is not performed, and performing leveling on the surface well Can do.

  In addition to the sixth characteristic configuration, the seventh characteristic configuration of the present invention is a position adjusting means for leveling device and a position adjusting means for leveling tool capable of changing and adjusting the vertical positions of the leveling device and the leveling tool separately. It is in that it is equipped with.

  According to the seventh characteristic configuration, the leveling device and the leveling tool both exhibit the leveling function for the surface of the field, but depending on the difference in the status of the surface, such as the difference in hardness of the field, the leveling device and the leveling tool It is also possible that there is a difference in leveling function between the two.

  Therefore, according to the difference in the situation of the surface, the leveling device and the leveling tool are adjusted to the appropriate vertical position that can exhibit a good leveling function by the position adjusting means for the leveling device and the position adjusting means for the leveling tool. Therefore, the leveling device and the leveling tool can exhibit a good leveling function.

It is a whole side view of a riding type rice transplanter. It is a side view of a seedling planting device and a leveling device. It is a front view of a seedling planting device and a leveling device. It is a top view of a seedling planting device and a leveling device. It is a side view of a raising / lowering operation mechanism. It is a perspective view of the rotary body for leveling. It is a side view of a float height detection mechanism. It is a side view of a leveling tool arrangement | positioning part. It is a front view of a leveling tool arrangement | positioning part. It is a top view of a leveling tool arrangement | positioning part. It is a perspective view of a transmission case. It is a control block diagram. It is a figure which shows the flow of an action | operation of a raising / lowering control means. It is a figure which shows the flow of an action | operation of a rolling control means. It is a figure which shows the flow of an action | operation of a leveling control means. It is operation | movement explanatory drawing of a 1st control state. It is operation | movement explanatory drawing of a 2nd control state. It is operation | movement explanatory drawing of a 3rd control state. It is a top view which shows the arrangement | positioning state of a leveling apparatus and a grounding float. It is a top view which shows the arrangement | positioning state of the leveling apparatus of another embodiment, and a grounding float. It is a side view of the sensor float front part of another embodiment.

  Hereinafter, the case where the embodiment of the paddy field machine according to the present invention is applied to a riding type rice transplanter will be described based on the drawings.

  As shown in FIG. 1, a six-plant type seedling planting device 5 (on the working device) is attached to the rear part of the traveling machine A supported by the right and left front wheels 1 and the right and left rear wheels 2. And a hydraulic lifting cylinder 4 as a driving means for driving the link mechanism 3 to move up and down is provided to constitute a riding type rice transplanter which is an example of a paddy field working machine. As will be described later, the seedling planting device 5 is configured to be movable up and down by a lifting cylinder 4 over a working position where it contacts the field surface G and a non-working position (upper limit position of the link mechanism 3) that is far away from the field surface G. ing.

Next, the seedling planting device 5 will be described.
As shown in FIGS. 1, 2, and 4, the seedling planting device 5 includes one feed case 17, three transmission cases 6, and a pair of rotation cases 7 that are rotatably supported at the rear part of the transmission case 6. , A pair of planting arms 8 provided at both ends of the rotating case 7, a ground float (hereinafter referred to as a center float) 9 functioning as a sensor float, and a ground float (hereinafter referred to as a center float) 9 11) (referred to as a side float) 11 and 6 seedling setting surfaces, and a seedling setting table 10 that is driven to reciprocally move laterally in the left-right direction, a vertical feed mechanism 25 provided on each of the seedling setting surfaces of the seedling setting table 10 and the like Configured. A feed case 17 and a transmission case 6 are fixed to a rectangular tubular main frame 18 extending in the left-right direction. The feed case 17 swings left and right around the front and rear axis P1 (see FIG. 3) at the lower rear portion of the link mechanism 3. It is supported freely.

  As shown in FIG. 4, the transverse feed shaft 19 extends from the feed case 17, and the end of the transverse feed shaft 19 is supported by the main frame 18 via the support member 20, and as the transverse feed shaft 19 rotates. A feed member 21 that is driven to reciprocate laterally is fitted on the transverse feed shaft 19, and the feed member 21 is connected to the seedling table 10. A guide rail 38 is supported by the transmission case 6 in the left-right direction, and a lower portion of the seedling bed 10 is supported along the guide rail 38 so as to be laterally movable. As shown in FIGS. 2 and 3, the vertical support member 26 is fixed to the right and left ends of the main frame 18 and extends upward, and the horizontal support member 50 is fixed over the upper portion of the vertical support member 26. The guide rail 27 is fixed to the front surface of the upper portion of the seedling platform 10, and the guide rail 27 is supported by a roller 51 supported by the lateral support member 50 so as to be movable laterally.

  As shown in FIGS. 1 and 4, the power of the engine 49 is transmitted to the input shaft 28 provided in the feed case 17 via the planting clutch 87 (see FIG. 12) and the PTO shaft 22. Power is transmitted to the lateral feed shaft 19 via the lateral feed speed change mechanism 29, and the lateral feed shaft 19 is rotationally driven. The power of the input shaft 28 is transmitted to the transmission chain 30, the transmission shaft 23 installed across the transmission case 6, and the input shaft 32 provided in the transmission case 6, and the power of the input shaft 32 is transmitted to the torque limiter 33, the transmission The rotation is transmitted to the rotary case 7 through the chain 34, the small number of clutches 24, and the drive shaft 35. A cylindrical cover 60 is fixed over the transmission case 6, and the transmission shaft 23 is covered by the cover 60.

  Thereby, when the planting clutch 87 is operated in the transmission state, the rotary case 7 is rotationally driven in the counterclockwise direction in FIG. The planting arms 8 alternately take out the seedlings from the bottom of the seedling platform 10 and plant them on the rice field G. When the planting clutch 87 is operated in the disconnected state, the reciprocating lateral feed drive of the seedling platform 10 and the rotational drive of the rotary case 7 are stopped.

  As shown in FIG. 2, a belt-type vertical feed mechanism 25 is provided on each of the six seedling setting surfaces of the seedling setting table 10. As shown in FIG. 4, the longitudinal feed shaft 36 extends from the feed case 17, and the end of the longitudinal feed shaft 36 is supported by the main frame 18 via the support member 37, and the longitudinal feed is performed by the power of the input shaft 28. The shaft 36 is rotationally driven, and a pair of drive arms 36 a are fixed to the longitudinal feed shaft 36. An input unit (not shown) for transmitting power to the six vertical feed mechanisms 25 is provided in the seedling bed 10, and the input unit is located between the drive arms 36 a of the vertical feed shaft 36. As a result, when the seedling bed 10 reaches the right or left end of the reciprocating lateral feed drive, the input portion reaches one drive arm 36a of the vertical feed shaft 36 and is input by one drive arm 36a of the vertical feed shaft 36. The parts are driven, and the seedlings on the seedling table 10 are sent downward by the six vertical feeding mechanisms 25.

  As shown in FIGS. 1 and 2, a hopper 12 that stores fertilizer and three feeding portions 13 each corresponding to two planting strips are provided on the rear side of the driver seat 31. A blower 14 is provided on the lower side. Two groovers 15 are fixed to the center float 9 and the side float 11, and six groovers 15 are provided. Six hoses 16 extend between the feeding portion 13 and the groover 15. Is connected. As a result, the fertilizer is fed from the hopper 12 by a predetermined amount by the feeding section 13 along with the seedling planting as described above, and the fertilizer is supplied to the groove producing device 15 through the hose 16 by the blower 14 blowing. Yes, fertilizer is supplied to the rice field G via the grooving device 15.

  As shown in FIG. 12, the feeding portion 13 is provided with a fertilizer clutch 90 that can transmit and shut the power freely, and an electric motor 91 that operates the fertilizer clutch 90 in a power-transmitted and shut-off state, and transmits the planting clutch 87. And the electric motor 89 which operates to the interruption | blocking state is provided. Thereby, by operating the planting and fertilization clutches 87, 90 to the transmission and shut-off state by the electric motors 89, 91, the operation of the seedling planting device 5 (planting of seedlings by the planting arm 8) and the feeding unit 13 and Stop.

Next, the leveling device 53 will be described.
As shown in FIG. 4, a boss member 64 is fixed to the left end of the main frame 18, and swings up and down around the horizontal axis P <b> 2 of the transmission shaft 23 and the input shaft 32 with respect to the boss member 64. A transmission case 81 is supported freely. On the other hand, a bracket 82 is fixed to the right end portion of the main frame 18, and the support arm 83 swings up and down around the horizontal axis P2 of the bracket 82 (the horizontal axis P2 of the transmission shaft 23 and the input shaft 32). The drive shaft 61 having a square cross section is rotatably supported across the transmission case 81 and the support arm 83.
As shown in FIG. 4, a leveling rotator 62 is externally fitted to the drive shaft 61 so as to be rotatably supported as a unit, and the leveling rotator 62 has large diameters different from each other in outer diameter. A leveling rotator 62A and a small-diameter leveling rotator 62B are provided.
And, in the leveling work area along the horizontal width direction of the aircraft, the center side of the horizontal width direction of the aircraft, and the area corresponding to the front side of the aircraft body of the center float 9 is provided with a small-diameter leveling rotary body 62B, and The small-diameter rotator 62B is provided with large-diameter rotators 62A on both the left and right sides.

  Each of the large-diameter leveling rotator 62A and the small-diameter leveling rotator 62B includes a plurality of large-diameter unit rotators 62Aa and small-diameter unit rotators 62Ba integrally formed of synthetic resin in the axial direction. They are arranged side by side.

  As shown in FIG. 6, the large-diameter unit rotating body 62Aa includes a boss portion 62a, a mounting hole 62b having a square cross section formed in the boss portion 62a, a flange portion 62c connected to the boss portion 62a, and a flange portion 62c. A convex leveling part 62d connected to the outer peripheral part is provided. Although not shown, the small-diameter unit rotating body 62Ba has the same configuration as the large-diameter unit rotating body 62Aa having a different size.

As shown in FIG. 5, the drive shaft 61 is inserted into the boss portions 62a (mounting holes 62b) of the plurality of large-diameter unit rotating bodies 62Aa and the plurality of small-diameter unit rotating bodies 62Ba, and the respective leveling rotating bodies 62A are inserted. 62B are externally fitted to the drive shaft 61 so as to be integrally rotatable, and a spacer 63 is externally fitted to the drive shaft 61 to determine the positions of the unit rotary bodies 62Aa and 62Ba in the axial direction.
As shown in FIGS. 4 and 19, between the small-diameter leveling rotary body 62 </ b> B located in the center of the machine body width direction and the large-diameter leveling rotary body 62 </ b> A located on the left and right sides, respectively. An interval is formed in the lateral direction of the machine body, and a gap S1 for passing muddy water is formed by this interval.

  As shown in FIG. 4, a bracket 65 is fixed to the transmission case 81 and the support arm 83, and a round pipe-shaped support frame 67 is fixed over each bracket 65. A mudguard cover 66 made of a soft synthetic resin that prevents mud from splashing on the seedling planting device 5 is attached and fixed to the support frame 67.

  As shown in FIG. 19, the rear end portion of the small-diameter cover portion 66B corresponding to the small-diameter leveling rotator 62B in the mudguard cover 66 has a rear end positioned at a large size corresponding to the large-diameter leveling rotator 62A. The small-diameter cover portion 66B and the large-diameter cover portion 66A of the mudguard cover 66 are configured by a split-type cover. A gap S2 for passing muddy water is formed between the small-diameter cover portion 66B and the large-diameter cover portion 66A.

  As shown in FIG. 2, the muddy water passage gap S2 has a predetermined left-right width between the outer end of the small-diameter cover portion 66B and the inside of the large-diameter cover portion 66A, and the small-diameter cover portion 66B. The outer end of the large-diameter cover portion 66A is positioned in front of the inner end of the large-diameter cover portion 66A.

  In the muddy water passage gap S2 shown in FIG. 19, the left and right widths of the muddy water passage gap S1 between the small-diameter leveling rotary body 62B and the large-diameter leveling rotary body 62A are set to the same horizontal width. However, the left and right width of the muddy water passage gap S2 may be set larger than the muddy water passage gap S1, and the left and right width of the muddy water passage gap S2 is smaller than the muddy water passage gap S1. May be set.

As a specific configuration for positioning the rear end portion of the small-diameter cover portion 66B on the front side of the machine body from the position of the rear end portion of the large-diameter cover portion 66A corresponding to the large-diameter grading rotating body 62A, As shown in FIG. 2, the cover portions 66A and 66B are attached to the cover attachment portion 67A provided on the support frame 67. The attachment positions of the cover portions 66A and 66B with respect to the cover attachment portion 67A are shifted back and forth. It can respond.
In addition, the cover mounting portions 67A corresponding to the cover portions 66A and 66B can be shifted back and forth by making the protruding lengths different. Furthermore, it can also be shifted back and forth by changing the attachment angle of the cover attachment portion 67A to the support frame 67.

  Further, as shown in FIG. 19, the position of the front end portion of the center frame 9 is set to the left and right side floats 11 (others) by the amount that the small diameter cover portion 66B is located on the front side of the machine body than the large diameter cover portion 66A. The grounding float is positioned in front of the airframe rather than the front end.

  Therefore, the leveling device 53 is constituted by the drive shaft 61, the leveling rotary body 62 (62A, 62B), the mudguard cover 66, the support frame 67, the transmission case 81, the support arm 83, and the like. A leveling device 53 is supported at the front part of the float 9 and the side float 11, and the leveling device 53 is disposed behind the rear wheel 2, and the transmission case 81 and the support arm 83 swing up and down around the horizontal axis P <b> 2. Thus, the leveling device 53 is supported by the front portion of the seedling planting device 5 so as to be movable up and down (corresponding to a state in which the leveling device is provided between the machine body and the paddy field work device). Therefore, the transmission case 81 and the support arm 83 correspond to the support portion F that supports the leveling device 53 with respect to the seedling planting device 5.

  As shown in FIG. 11, the lower end of the transmission case 81 and the support arm 83 that support the leveling device 53 has a triangular shape in plan view in order to prevent mud on the surface G from coming into sliding contact and accumulation. A mudguard member 92 is provided that is formed by bending a plate material so that the tip has an acute angle. By providing the mudguard member 92, it is possible to avoid that the transmission case 81 and the lower end portion of the support arm 83 are in contact with the surface G and are mud pushed or damaged by contact with the surface G.

A leveling tool 93 for leveling the field G is provided in a state overlapping with the support portion F (the transmission case 81 and the support arm 83) in plan view.
That is, as shown in FIGS. 8, 9, and 10, a horizontal axis is provided via a support bracket 95 on a frame portion 94 provided so as to extend outward from the left and right side ends of the main frame 18. A rake-shaped leveling tool 93 is supported in a state in which it can swing around the core and swing downwardly by a torsion spring 96.
The leveling action area by the leveling tool 93 is arranged in a state of overlapping with the transmission case 81 and the support arm 83 in plan view as described above, but the leveling action area by the leveling tool 93 is equipped with auxiliary wheels (not shown). In this case, the leveling area is set so as to level the trace of passage of the auxiliary wheel.

  The support bracket 95 is configured to include an attachment portion 95A for attachment to the frame portion 94, and a U-shaped pivot support portion 95B for pivotally supporting the leveling tool 93 in a swingable manner. The rake-shaped leveling action part 93A, the mounting vertical plate part 93B integrally connected to the leveling action part 93A, and screwed to the vertical plate part 93B and fixed to the pivotal support part 95B A U-shaped connecting portion 93 </ b> C that is pivotally supported by a support shaft 97 in a plan view.

A torsion spring 96 is externally fitted to the support shaft 97, and one end of the torsion spring 96 comes into contact with the leveling tool 93 so that the other end side of the torsion spring 96 can be locked and held. That is, the other end portion of the torsion spring 96 extends outward through the opening formed in the pivotal support portion 95B, but is configured to be held and held by the spring receiving portion 98 formed in the opening. It is restricted that 93C contacts the pivotal support portion 95B against the biasing force of the torsion spring 96 and the leveling tool 93 freely swings downward.
That is, the leveling tool 93 is supported while being moved and urged downward by the urging force of the torsion spring 96 and being held at a predetermined position. By changing, the downward biasing force can be changed and adjusted in three stages.

Further, the leveling action portion 93A is fixed by screwing to the connecting portion 93C, but the screw passage hole 99 provided in the leveling action portion 93A is formed as a long hole in the vertical direction, and the leveling action portion is loosened by loosening the screw. The relative position can be changed by sliding the 93A in the vertical direction, and the predetermined position can be changed and adjusted up and down.
Accordingly, the vertical position and the downward biasing force of the leveling tool 93 can be changed and adjusted according to the state of the field, and the position adjusting mechanism K2 for adjusting the position of the leveling tool 93 as described above is provided. This corresponds to the position adjusting means for the leveling tool 93.

Next, the drive structure of the leveling device 53 will be described.
As shown in FIG. 4, a transmission shaft 75 connected to the input shaft 32 provided in the transmission case 6 is disposed inside the boss member 64 and the transmission case 81. Inside the transmission case 81, a sprocket 78 is fitted on the transmission shaft 75 so as to be relatively rotatable, a sprocket 79 is fixed to the drive shaft 61, and a transmission chain 80 is wound around the sprockets 78, 79. A torque limiter 77 is provided between the transmission shaft 75 and the sprocket 78.

  As shown in FIGS. 1 and 4, when the power of the engine 49 is transmitted to the input shaft 28, the transmission chain 30, the transmission shaft 23 and the input shaft 32 via the planting clutch 87 and the PTO shaft 22, the input shaft 32 is transmitted to the drive shaft 61 through the transmission shaft 75, the torque limiter 77, and the transmission chain 80, and the drive shaft 61 and the leveling rotators 62A and 62B are rotationally driven in the counterclockwise direction in FIG. .

  In this case, the drive shaft 61 and the leveling rotators 62A and 62B are rotationally driven at a speed higher than the traveling speed of the machine body (the leveling rotator 62A and the leveling rotator 62A, more than the peripheral speed of the outer periphery of the right and left rear wheels 2). 62B is rotationally driven so that the peripheral speed of the outer periphery of 62B becomes high). As a result, the field G in front of the planting arm 8 is leveled (scraped) by the drive shaft 61 and the leveling rotators 62A and 62B, and seedling planting behind the drive shaft 61 and the leveling rotators 62A and 62B. Mud scattering to the attaching device 5 is prevented by the mudguard cover 66.

  By operating the planting and fertilization clutches 87, 90 to the transmission and shut-off states by the electric motors 89, 91, the seedling planting device 5 and the feeding unit 13 are activated and stopped, and at the same time, the operation of the leveling device 53 and Stop. When a large load is generated on the drive shaft 61 and the leveling rotators 62A and 62B due to foreign matter such as stones being caught in the drive shaft 61 and the leveling rotators 62A and 62B, the torque limiter 77 causes the drive shaft 61 and The power to the leveling rotators 62A and 62B is cut off, and the drive shaft 61 and the leveling rotators 62A and 62B are stopped.

  As shown in FIGS. 3 and 5, the leveling device 53 is placed between the small-diameter leveling rotary body 62 </ b> B and the large-diameter leveling rotary body 62 </ b> A located on the left side in the traveling direction. Is provided with an elevating operation mechanism K1 (an example of a position adjusting means for a leveling device) that can be operated up and down.

Next, the lifting operation mechanism K1 will be described.
As shown in FIG. 5, a support frame 52 is fixed to the main frame 18, and a fan-shaped elevating gear 54 is supported around the horizontal axis P3 of the support frame 52 so as to be swingable up and down, and includes a pinion gear 55a. The gear mechanism 55 and an electric motor 56 as a leveling height adjusting means for driving the gear mechanism 55 are fixed to the support frame 52.
Between the small-diameter leveling rotary body 62B and the large-diameter leveling rotary body 62A located on the left side in the traveling direction, a boss member 57 is attached to the drive shaft 61 so as to be relatively rotatable by a bearing (not shown). It is fitted. Then, the pinion gear 55a of the gear mechanism 55 is engaged with the elevating gear 54, the connecting member 58 is connected across the elevating gear 54 and the boss member 57, and the pinion gear 55a is rotationally driven by the electric motor 56, thereby being connected. The member 58 is moved up and down, and the leveling device 53 is moved up and down.

  In other words, the pinion gear 55a of the gear mechanism 55 is driven to rotate forward and backward by the electric motor 56, and the lifting gear 54 is driven to swing up and down around the horizontal axis P3. On the other hand, it can be driven up and down.

  As shown in FIG. 19, a muddy water passage gap S1 is formed between the small-diameter leveling rotary body 62B and the large-diameter leveling rotary body 62A located on both the left and right sides. The muddy water is not swept away outward, and can be guided in the front-rear direction toward the left and right sides of the center float 9 through the muddy water passage S1.

As shown in FIG. 12, in the state where the seedling planting device 5 is located at the working position, the retraction position where the small-diameter leveling rotary body 62B and the large-diameter leveling rotary body 62A are located above the rice field G, respectively. The leveling device 53 can be driven up and down by the electric motor 56 in the range of the work position A4 that contacts A3 and the surface G.
If the seedling planting device 5 is located at a non-working position that swings upward greatly, the leveling device 53 will not contact the surface G even if the leveling device 53 is driven down to the work position A4.

  Incidentally, a coil spring 59 is connected across the bracket 65 and the support member 26 on both the left and right sides, and the leveling device 53 is urged upward by the urging force of the coil spring 59.

  As shown in FIGS. 5 and 12, the leveling height detector 74 is fixed to the support frame 52 so as to be positioned on the horizontal axis P3, and the leveling height detector 74 and the lifting gear 54 are connected. The detected value of the leveling height detector 74 is input to the control device 40. Thus, the height of the leveling device 53 relative to the seedling planting device 5 is detected by detecting the angle of the elevating gear 54 with respect to the support frame 52 by the leveling height detector 74.

  Further, as shown in FIG. 12, an artificially operable dial-type leveling height setting device 84 is provided, and an operation position of the leveling height setting device 84 is input to the control device 40, which will be described later. Thus, the leveling target height B3 (leveling depth) can be arbitrarily set by operating the leveling height setting unit 84.

  As shown in FIG. 5, a support shaft 41 is rotatably supported around a horizontal axis P4 at the bottom of the transmission case 6, and a support arm 41a fixed to the support shaft 41 extends rearward. Around the horizontal axis P5 at the rear end of the arm 41a, the rear portions of the center float 9 and the side float 11 are supported so as to be swingable up and down. As shown in FIGS. 3 and 7, a planting setting height lever 42 as an artificially operable working depth setting means is fixed to the support shaft 41 and extends forward and upward, and the main frame 18. A planting setting height lever 42 is inserted into the lever guide 43 fixed to the.

  By rotating the support shaft 41 and the support arm 41a with the planting setting height lever 42 and engaging the planting setting height lever 42 with the lever guide 43, the horizontal axis P5 (the center float 9 and the side float 9). The height of the seedling planting device with respect to the rice field, that is, the seedling planting depth by the planting arm 8 can be changed.

  As shown in FIG. 12, a potentiometer type planting depth detector 44 for detecting the angle of the support shaft 41 is fixed to the main frame 18, and the detection value of the planting depth detector 44 is input to the control device 40. Has been. By detecting the angle of the support shaft 41 with the planting depth detector 44, the position of the horizontal axis P5 (the swing fulcrum of the center float 9 and the side float 11) can be detected. In addition, when the set height A1 (set depth) is set by the planting set height lever 42, the set height A1 (set depth) is recognized by the control device 40 based on the detection value of the planting depth detector 44. Is done.

  The control device 40 is configured to include a microcomputer, and the control device 40 sets the height of the seedling planting device 5 relative to the surface G based on the vertical movement accompanying the fluctuation of the ground pressure of the center float 9 to the set height A1 (set Elevating control for controlling the elevating cylinder 4 to maintain the depth), rolling control for maintaining the right / left inclination angle of the seedling planting device 5 at a set angle, and leveling for controlling the operation of the electric motor 56 for elevating operation It is comprised so that various control of control may be performed. That is, using the control device 40, the elevation control means 100, the rolling control means 101, and the leveling control means 102 are configured.

Next, a configuration for executing the lifting control will be described.
As shown in FIG. 7, in the clearance S2 between the small-diameter leveling rotator 62B and the large-diameter leveling rotator 62A located on the right side in the traveling direction, a variation in the ground pressure of the center float 9 is caused. A float height detection mechanism K3 for detecting the displaced vertical height position is provided.

  As shown in FIG. 19, the ground leveling rotary body 62 </ b> B has a center position CL <b> 2 in the body width direction of the center float 9 and one side in the body width direction toward the traveling direction with respect to the center position CL <b> 1 in the body width direction of the center float 9. In the example shown in FIG. 19, the center position CL2 of the center-floor rotating body 62B having a small diameter with respect to the center position CL1 of the center float 9 with respect to the center position CL1 of the center float 9 is displaced. The float height detection mechanism K3 is provided by effectively utilizing the gap S2 provided in a state approaching the center position in the lateral width direction of the vehicle body by offsetting the left and right sides.

  Since the float height detecting mechanism K3 is provided by effectively using the gap S2 in this way, the float height detecting mechanism K3 and the center float 9 can be laid out in a short distance, and the float height can be increased. The detection accuracy by the height detection mechanism K3 can be increased, and a delay in sensing time can be reduced. In addition, since the center float 9 functioning as a sensor float is most sensitive and important, the small-diameter rotator 62B for leveling is disposed at the center position of the machine body. Therefore, the detection accuracy can be improved by leveling.

  As shown in FIG. 7, the float height detection mechanism K3 has a potentiometer type float height detector 68 fixed to a bracket 67, and can be rotated integrally with an operation shaft of the float height detector 68 and operated. A detection arm 68 a is attached so as to be able to swing the balance around the axis of the shaft, and a push-pull rod 69 is interlocked between one end portion of the detection arm 68 a and the front portion of the center float 9. The movement can be detected by the float height detector 68. A coil spring 86 that biases the push-pull rod 69 downward is provided at the other end of the detection arm 68a, and the front portion of the center float 9 is biased downward by the coil spring 86.

  Then, as shown in FIG. 12, the detection value C1 of the float height detector 68 is input to the control device 40, and a dial-type sensitivity setting device 70 that can be artificially operated is provided. The operation position is input to the control device 40.

Next, the operation of the elevation control means 100 will be described based on FIG.
First, in the state where the seedling planting device 5 is located at the work position, the set height A1 (set depth) is detected from the detection value of the planting depth detector 44 (step S1), and the set height A1. A lift target value B1 corresponding to (set depth) is set (step S2).

  The target elevation value B1 can be changed by the sensitivity setting unit 70. That is, if the sensitivity setter 70 is operated to the neutral position N at the center of the sensitive side and the insensitive side, there is no change in the lift target value B1, but if the sensitivity setter 70 is operated from the neutral position N to the insensitive side, When the elevation target value B1 is changed to a higher side corresponding to the operation position of the sensitivity setting device 70 and the sensitivity setting device 70 is operated from the neutral position N to the sensitive side, the elevation target value B1 is changed to the operation position of the sensitivity setting device 70. Correspondingly, it is changed to a slightly lower side (steps S3 to S5).

As a result, when the sensitivity setting unit 70 is operated from the neutral position N to the sensitive side, the bottom surface of the center float 9 is slightly moved when the detection value C1 of the float height detector 68 becomes the same height as the elevation target value B1. Since the center float 9 follows the field surface G sensitively, the raising / lowering drive of the seedling planting device 5 by the raising / lowering cylinder 4 is set to be sensitive.
When the sensitivity setting device 70 is operated from the neutral position N to the insensitive side, the bottom surface of the center float 9 rises slightly forward when the detection value C1 of the float height detector 68 reaches the same height as the lift target value B1. Since the ground contact area of the center float 9 to the rice field G becomes small and the center float 9 follows the rice field G in an insensitive manner, the raising and lowering drive of the seedling planting device 5 by the elevating cylinder 4 is insensitive. Set to

When the center float 9 follows the ground surface G and the seedling planting device 5 moves up and down, the height from the surface G (center float 9) to the seedling planting device 5 (planting arm) is moved accordingly. 8), the front side of the center float 9 swings up and down, and the vertical swing amount is transmitted to the float height detector 68 by the push-pull rod 69.
Therefore, the height from the rice field G (center float 9) to the seedling planting device 5 (planting depth of the seedling by the planting arm 8) is detected by the detection value of the float height detector 68 (step S6), A difference E1 between the ascending / descending target value B1 and the detected value C1 of the float height detector 68 is obtained (step S7).

When the detection value C1 of the float height detector 68 is higher than the lift target value B1 (step S8), the control valve 71 for supplying and discharging the hydraulic oil to and from the lift cylinder 4 is operated and the lift cylinder 4 is used to plant seedlings. The device 5 is driven downward (step S9).
When the detected value C1 of the float height detector 68 is the same height as the lift target value B1 (step S8), the control valve 71 is operated to stop the lift drive of the seedling planting device 5 (step S10).
When the detection value C1 of the float height detector 68 is lower than the lift target value B1 (step S8), the control valve 71 is operated to drive the seedling planting device 5 up by the lift cylinder 4 (step S11).

  That is, the seedling planting device 5 is driven up and down by the lift cylinder 4 so that the detection value C1 of the float height detector 68 becomes the lift target value B1, and the seedlings by the seedling planting device 5 (planting arm 8) are driven. The planting depth is maintained at the set depth.

  By executing the elevation control as described above, if the position of the horizontal axis P5 (the swing fulcrum of the center float 9 and the side float 11) is changed by the planting setting height lever 42, a new set height A1 ( Since the set depth) is set, a new lift target value B1 corresponding to the new set height A1 (set depth) is set accordingly, thereby the seedling planting device 5 (planting) The planting depth of the seedling by the attached arm 8) can be changed.

Next, a configuration for executing rolling control will be described.
As shown in FIG. 3, the feed case 17 is supported in a freely rolling manner around the front and rear axis P <b> 1 at the lower rear part of the link mechanism 3 (the seedling planting device 5 is around the front and rear axis P <b> 1 at the lower rear part of the link mechanism 3. Is supported to roll freely). As shown in FIGS. 3 and 7, the tilt sensor 48 is fixed to the feed case 17, and the tilt angle in the left-right direction of the seedling planting device 5 with respect to the horizontal plane (field G) is detected by the tilt sensor 48. The detection value C2 of the sensor 48 is input to the control device 40.

As shown in FIG. 3, a rolling mechanism 46 is provided at the upper rear portion of the link mechanism 3. The rolling mechanism 46 is a pair of wires 46a that are pushed and pulled in the left-right direction, and a gear mechanism that pushes and pulls the wires 46a. (Not shown) and an electric motor 46b for operating the gear mechanism.
A bracket 27a is fixed to the right and left ends of the guide rail 27, and a balance spring 47 is connected between the arm 46c fixed to the rolling mechanism 46 and the bracket 27a of the guide rail 27, and the rolling mechanism A spring 39 is connected across the wire 46 a of 46 and the right and left side portions of the lateral support member 50. The right or left balance spring 47 is extended as the seedling platform 10 is driven to reciprocate laterally. When the seedling platform 10 is laterally driven to the right (left), the right (left) ) Is extended, and the urging force of the right (left) balance spring 47 suppresses the inclination of the seedling planting device 5 to the right (left).

Next, the operation of the rolling control means 100 will be described with reference to FIG.
In a state where the seedling planting device 5 is located at the work position, the tilt angle of the horizontal direction of the seedling planting device 5 with respect to the horizontal plane (field G) is detected by the tilt sensor 48 (step S12), and the horizontal plane and the tilt sensor 48 are detected. A difference E2 from the detected value C2 is obtained (step S13).

  When the seedling planting device 5 is displaced from the horizontal plane to the right slope side (step S14), the electric motor 46b of the rolling mechanism 46 is operated and the wire 46a of the rolling mechanism 46 is pushed and pulled to drive the seedling planting device. 5 is driven to roll to the left around the longitudinal axis P1 (step S15).

  When the seedling planting device 5 is displaced from the horizontal plane to the left inclined side (step S14), the electric motor 46b of the rolling mechanism 46 is operated and the wire 46a of the rolling mechanism 46 is pushed and pulled to drive the seedling planting device. 5 is driven to roll rightward around the longitudinal axis P1 (step S16). If the seedling planting device 5 has the same inclination angle as the horizontal plane, the rolling drive of the seedling planting device 5 is stopped (step S17). In this way, the seedling planting device 5 is maintained horizontally (maintained parallel to the field G in the left-right direction).

Next, the leveling control means 102 will be described.
The leveling control means 102 is a first control state in which the operation of the electric motor 56 is controlled so that the lower end t1 of the small-diameter leveling rotary body 62B is positioned above the bottom surface position t2 of the center float 9. In the second control state in which the operation of the electric motor 56 is controlled so that the lower end t1 of the rotating body 62B is positioned at the same height as the bottom surface position t2 of the center float 9, the lower end t1 of the small-diameter rotating body 62B is centered. It is configured to be switchable to each of the third control states in which the operation of the electric motor 56 is controlled so as to be positioned below the bottom surface position t2 of the float 9.

  Further, the leveling control means 102 positions the lower end t1 of the small-diameter leveling rotator 62B above the bottom surface position t2 of the center float 9, and the lower-end t3 of the large-diameter leveling rotator 62A on the side. It is configured to be switchable to a retreat control state for controlling the operation of the electric motor 56 so as to be located at the retreat position A3 located above the bottom surface position t4 of the float 11.

  Even if the leveling control means 102 is switched to any one of the first control state, the second control state, and the third control state, the lower end t3 of the large-diameter leveling rotary body 62A is It is configured to be positioned below the bottom surface position t4.

  When the explanation is added, as shown in FIG. 17, when the leveling height setting unit 84 is operated to the “standard” position, the leveling target height B3 corresponding to the standard state is set, and the leveling height setting unit 84 is set to “standard”. ”To the left of the“ position ”, the leveling target height B3 shallower than the leveling target height 3 corresponding to the standard state is set, and if operated to the right of the“ standard ”position, the leveling target height corresponding to the standard state is set. The leveling target height B3 deeper than the height B3 is set.

  As shown in FIG. 17, the standard state is a state where the lower end t <b> 1 of the small-diameter leveling rotary body 62 </ b> B is located at the same height as the bottom surface position t <b> 2 of the center float 9. When the leveling height setting unit 84 is operated to the left of the “standard” position, the lower end t1 of the small-diameter leveling rotary body 62B is positioned above the bottom surface position t2 of the center float 9 (see FIG. 16). ). The state in which the leveling height setting device 84 is operated to the right side of the “standard” position is a state in which the lower end t1 of the small-diameter leveling rotary body 62B is positioned below the bottom surface position t2 of the center float 9 (FIG. 18). Here, the bottom surface position t2 of the center float 9 is the position of the bottom surface corresponding to the position immediately below the lateral axis P5 (swinging fulcrum position) of the sensor float 9.

  The operation of the leveling control means 102 will be described based on FIG. However, the operation of the leveling control means 102 is executed in a state where the seedling planting device 5 is located at the work position, the leveling device 53 is located at the work position A4, and the elevation control means 100 and the rolling control means 101 are activated. Will be.

  First, it is determined whether the leveling height setting unit 84 is set to the “standard” position or any other position (step S51). If it is set to the “standard” position, the planting depth is detected. The set height A1 (set depth) is obtained from the detection value of the device 44 (step S52), and the lower end t1 of the small-diameter rotator 62B and the bottom surface position t2 of the center float 9 have the same height. The leveling target height B3 is set (step S53).

  When the description is added, as shown in FIG. 17, the bottom surface position t2 corresponding to the position just below the lateral axis P5 corresponding to the swing fulcrum position of the center float 9 and the lower end t1 of the small-diameter leveling rotary body 62B are the same. The lower end t1 of the small-diameter leveling rotary body 62B and the bottom surface position t2 of the center float 9 have the same height from the set height A1 when the center float 9 is in the horizontal posture so as to be the height. The leveling target height B3 is set. More specifically, the relational expression or map data between the set height A1 and the leveling target height B3 when the lower end t1 of the small-diameter leveling rotary body 62B and the bottom surface position t2 of the center float 9 are the same height. Is obtained and stored in advance, and the leveling target height B3 can be set from the relational expression and map data and the set height A1.

  When the leveling height setting unit 84 is at a position other than the “standard” position, for example, when the leveling height setting unit 84 is operated to the right of the “standard” position (when operated to the deep side). Then, the set height A1 (set depth) is obtained from the detection value of the planting depth detector 44 (steps S54 and 55), and the lower end t1 of the small-diameter rotating body 62B is from the bottom surface position t2 of the center float 9. Is also set to the leveling target height B3 for lowering (step S56).

  When the description is added, as shown in FIG. 18, the lower end t1 of the small-diameter rotating body 62B for leveling is located below the bottom surface position t2 corresponding to the position immediately below the horizontal axis P5 of the center float 9, and Based on the set height A1 when the center float 9 is in the horizontal posture and the turning operation amount of the leveling height setting device 84 so that the higher the turning operation amount of the leveling height setting device 84 is, the lower the position is. Then, the leveling target height B3 is set. Also in this case, the leveling target height B3 is set using the map data as described above.

  When the leveling height setter 84 is operated to the left of the “standard” position (when operated to the deep side), the set height A1 (set depth) is determined by the detection value of the planting depth detector 44. ) (Step S57), and the leveling target height B3 is set so that the lower end t1 of the small-diameter leveling rotary body 62B is located above the bottom surface position t2 of the center float 9 (step S58).

  When the description is added, as shown in FIG. 16, the lower end t1 of the small-diameter rotating body 62B for leveling is positioned above the bottom surface position t2 corresponding to the position immediately below the horizontal axis P5 of the center float 9, and Based on the set height A1 when the center float 9 is in the horizontal position and the turning operation amount of the leveling height setting device 84 so that the higher the turning operation amount of the leveling height setting device 84 is, the higher the position is. Then, the leveling target height B3 is set. Also in this case, the leveling target height B3 is set using the map data as described above.

  Further, as shown in FIGS. 16 to 18, even when the leveling height setting device 84 is operated to the left of the “standard” position at the maximum, the lower end t3 of the large-diameter leveling rotary body 62A is The adjustment range is set so as to be positioned below the bottom surface position t4 of the side float 11. As a result, when the leveling height setting unit 84 is set to the “standard” position, it is operated to the left of the “standard” position, or to the right of the “standard” position. Even in this case, the lower end t3 of the large-diameter rotating body 62A for leveling is configured to be positioned below the bottom surface position t4 of the side float 11.

  When the sensitivity setting unit 70 is operated to the neutral position N, the leveling target height B3 set by the leveling height setting unit 84 is maintained, but when the sensitivity setting unit 70 is operated to the insensitive side, the leveling height is increased. The leveling target height B3 set by the height setting device 84 is changed to a slightly lower side (state where the leveling depth of the leveling device 53 becomes deeper) (steps S59 and S60). When the sensitivity setting unit 70 is operated to the sensitive side, the leveling target height B3 set by the leveling height setting unit 84 is changed to a slightly higher side (state where the leveling depth of the leveling device 53 becomes shallow). (Step S61).

  Then, the height of the leveling device 53 relative to the seedling planting device 5 is detected from the detection value of the leveling height detector 74, and the difference E3 between the leveling target height B3 and the detection value C3 of the leveling height detector 74 is obtained. (Steps S62, 63).

When the detection value C3 of the leveling height detector 74 is higher than the leveling target height B3 (step S64), the electric motor 56 is operated so that the detection value C3 becomes the leveling target height B3, thereby the leveling device 53. Is driven downward (step S65).
When the detected value C3 of the leveling height detector 74 is the same height as the leveling target height B3 (step S64), the elevation drive of the leveling device 53 is stopped (step S66).
If the detected value C3 of the leveling height detector 74 is lower than the target leveling height B3 (step S64), the electric motor 56 is operated so that the detected value C3 becomes the leveling target height B3, and the leveling device 53 is operated. Is driven up (step S67).

In other words, the electric motor 56 is driven so that the leveling depth of the leveling device 53 is maintained at the leveling target height B3 so that the detection value C3 of the leveling height detector 74 becomes the leveling target height B3.
The state where the leveling height setting unit 84 is operated to the left of the “standard” position corresponds to the first control state, and the state where the leveling height setting unit 84 is set to the “standard” position is the second. Corresponding to the control state, a state in which the leveling height setting unit 84 is operated to the right side of the “standard” position corresponds to the third control state.

  By executing the leveling control as described above, when the position of the horizontal axis P5 (the swing fulcrum of the center float 9 and the side float 11) is changed by the planting setting height lever 42, the new setting height A1 is obtained. The corresponding new leveling target height B3 is set, whereby the leveling depth of the leveling device 53 can be changed.

[Another embodiment]
(1) In the above embodiment, the mudguard cover 66 is composed of a split type cover divided into the small diameter cover portion 66B and the large diameter cover portion 66A. Are provided in a continuous manner over the entire width in the lateral direction of the fuselage, and a notch recess or penetrating hole for passing muddy water through the step portion in the front-rear direction between the small-diameter cover portion 66B and the large-diameter cover portion 66A. A hole may be formed.

(2) In the above embodiment, a soft synthetic resin material is used as the material of the mudguard cover 66, but instead of such a configuration, a different material such as a rubber plate, a hard synthetic resin material, a thin steel plate, or the like. May be used.

(3) In the above embodiment, the small-diameter cover is configured such that the position of the rear end portion of the small-diameter cover portion 66B in the mudguard cover 66 is positioned more forward than the position of the rear end portion of the large-diameter cover portion 66A. For example, the shape and material of the small-diameter cover portion 66B and the large-diameter cover portion 66A may be different, or the small-diameter cover may be used in addition to changing the attachment form of the portion 66B and the large-diameter cover portion 66A to the cover attachment portion 67A. It is good also as a structure which changes direction with the attaching plate for attaching the part 66B and the large diameter cover part 66A to the cover attaching part 67A.

(4) In the above embodiment, the muddy water passage gap S1 is formed between the large-diameter leveling rotary body 62A and the small-diameter leveling rotary body 62B. However, such a gap is provided. There may be no configuration.

(5) In the above embodiment, the small-diameter leveling rotator 62B is positioned on the center side in the horizontal direction of the machine body, and the large-diameter leveling rotator 62A is positioned on the left and right sides of the small-diameter leveling rotator 62B. As shown in FIG. 20, a large-diameter leveling rotary body 62A is positioned on the center side in the body width direction, and a small-diameter leveling rotary body 62B is a large-diameter leveling rotary body. 62A may be arranged so as to be positioned on both the left and right sides of the 62A, and the left and right side floats 11 may function as sensor floats. In this case, the average value of the float height detection values on the left and right sides can be used as the height detection value.

(6) The center float 9 in the above embodiment may be configured as follows.
As shown in FIG. 21, a flat plate-like support member 9A is connected to the front portion of the center float 9, and extends forward through the lower side of the drive shaft 61 in the gap S1 of the leveling device 53 and the gap S2 of the mudguard cover 66. It is good also as a structure which connects small float 9B to member 9A.

(7) In the above embodiment, as the control by the leveling control means 102, the leveling target height B3 is changed according to the set value of the sensitivity setting unit 70, and the detection value C3 of the leveling height detector 74 is changed. Although the configuration is shown in which the processing (steps 59 to 67) for operating the electric motor 56 so as to reach the leveling target height B3 is shown, such a configuration may not be performed.

(8) In the above-described embodiment, the seedling planting device 5 is shown as the working device, but a fertilizer, a direct sowing device, a chemical spraying device, a rice bran spraying device, and the like that supply paste-like fertilizer to the rice field may be provided.

(9) In the above embodiment, the leveling device 53 is supported by the work device (the seedling planting device 5), but the ground leveling device 53 is not supported by the work device (the seedling planting device 5), but the machine body. You may comprise so that the leveling apparatus 53 may be supported by the link mechanism (not shown) extended from the rear part.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a paddy field work machine in which a work device is provided at a rear portion of a traveling machine body such as a riding type rice transplanter so as to be movable up and down, and a leveling device is provided between the traveling machine body and the work apparatus.

4 Lifting drive means 5 Working device 9, 11 Ground float 9 Sensor float 53 Leveling device 62A Large diameter leveling rotary body 62B Small diameter leveling rotary body 66 Mudguard cover 66A Large diameter cover portion 66B Small diameter cover portion 93 Leveling tool DESCRIPTION OF SYMBOLS 100 Elevation control means A Traveling machine body F Support part K1 Position adjustment means K2 for leveling equipment Position adjustment means P5 for leveling tools Horizontal axis S1, S2 Crevice

Claims (7)

A working device is provided at the rear of the traveling machine body so that it can be lifted and lowered by a lifting drive means, and a leveling device is provided between the traveling machine body and the working device,
The leveling device is a paddy field work machine configured to include a leveling rotator that is driven to rotate around a horizontal axis and a mudguard cover that prevents mud from splashing on the work device,
The leveling device comprises a large-diameter leveling rotator and a small-diameter leveling rotator having different outer diameters in a state of being driven and rotated around the same horizontal axis,
In the mudguard cover, the small-diameter cover portion corresponding to the small-diameter leveling rotator has a rear end position that is larger than the rear-end position of the large-diameter cover portion corresponding to the large-diameter leveling rotator. A paddy field work machine provided in a state of being positioned on the front side of the machine body, and having a gap for passing muddy water formed between the small diameter cover portion and the large diameter cover portion.   The paddy field machine according to claim 1, wherein the small-diameter cover portion and the large-diameter cover portion of the mudguard cover are constituted by a split type cover.   The paddy field machine according to claim 1 or 2, wherein a gap for passing muddy water is formed between the large-diameter leveling rotator and the small-diameter leveling rotator. Any one of a plurality of grounding floats provided in the working device is configured as a sensor float that swings up and down around the lateral axis of the rear portion while following the grounding and detects the ground height of the working device,
Elevation control means for controlling the elevating drive means to maintain the height of the working device relative to the surface based on the vertical swing of the sensor float at a set value is provided,
Of the leveling work area along the horizontal width direction of the machine body, the area corresponding to the front side of the machine body of the sensor float is provided with the rotating body for leveling the small diameter,
The paddy field work machine according to any one of claims 1 to 3, wherein the sensor float is provided in a state in which a position of a front end portion thereof is positioned on a front side of a machine body from a position of a front end portion of another grounding float. .   The small-diameter leveling rotator is positioned on the center side in the lateral direction of the fuselage, and the large-diameter leveling rotator is positioned on both the left and right sides of the small-diameter leveling rotator. The paddy field work machine according to any one of 4. The leveling device is supported by the working device by a support portion;
The paddy field work machine according to any one of claims 1 to 5, wherein a leveling tool for leveling the paddy surface is provided in a state of overlapping with the support portion in plan view.   The paddy field work machine according to claim 6, further comprising position adjusting means for the leveling apparatus and position adjusting means for the leveling tool, each of which is capable of changing and adjusting the vertical position of each of the leveling apparatus and the leveling tool.

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