Seedling transplanter

Abstract

To provide a seedling transplanter which can obtain the excellent followability to a seedling transplanting tool that moves up / down with a relatively simple configuration related to a cleaning device that removes soil and the like adhering to the seedling transplanting tool and can perform the accurate operation synchronized with the operation of the seedling transplanting tool.SOLUTION: A seedling transplanter which includes a seedling planting device equipped with a hole opener 40 that moves up / down to plant seedlings in a farm field, includes: a scraper device 100 which has scrapers 102 (inner scraper 102A, front scraper 102B, rear scraper 102C) that act on the hole opener 40 and that remove soil and the like adhering to the hole opener 40 with the scrapers 102; and a drive cam 101 which operates the scraper device 100 so as to make the scrapers 102 act on the hole opener 40 by acting on the scraper device 100 following the upward movement of the hole opener 40.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a seedling transplanter that continuously plants seedlings in a field while moving. [Background technology]

[0002] Conventionally, in a seedling transplanter that performs seedling planting work by continuously planting seedlings in a field while moving, the seedling planting device is configured to have a seedling planting tool (hole opener) that is configured to be able to open and close like a beak by a pair of planting claws that are planting bodies and moves up and down while tracing a predetermined trajectory. The seedling planting tool receives seedlings from a seedling supply unit in a raised state, descends to enter the field, opens the pair of planting claws to release the seedlings into planting holes formed in the field, and plants the seedlings in the field.

[0003] Among seedling transplanters equipped with such seedling planting devices, there are some equipped with a cleaning device that removes soil, mud, etc. that has adhered to the inside of a pair of planting claws of the seedling planting tool (see, for example, Patent Document 1 and Patent Document 2). The cleaning device has a scraper as a cleaning body made of rubber or the like, and acts on the seedling planting tool at a predetermined timing in accordance with the operation of the seedling planting tool, scraping off and removing soil, etc., that has adhered to the seedling planting tool with the scraper.

[0004] Patent Document 1 discloses a configuration in which a scraper is positioned in the space between a pair of planting claws of a seedling planting tool that rises while closing the open pair of planting claws, and the scraper is lowered relative to the rising seedling planting tool while acting on the inside of the seedling planting tool, thereby scraping off soil and the like from inside the seedling planting tool. In the configuration disclosed in Patent Document 1, the scraper is attached to the tip of a support arm that is biased by a tension spring for rotational motion, and moves by the biased rotation of the support arm to position itself in the space between the pair of planting claws.

[0005] Patent Document 2 discloses a configuration in which a scraper is provided at the tip of an arm that swings up and down in conjunction with the raising and lowering movement of the seedling planting tool by a cam mechanism provided on a drive shaft protruding from a planting transmission case that drives the seedling planting device. In this configuration, the scraper fits laterally into the inside of the seedling planting tool and remains there as the seedling planting tool rises in an open state due to the swinging of the arm, and acts to scrape off soil and the like inside the seedling planting tool as the seedling planting tool rises, and then moves sideways and escapes from inside the seedling planting tool before the seedling planting tool closes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3948374 [Patent Document 2] Patent No. 5793959 Summary of the Invention [Problem to be solved by the invention]

[0007] The seedling transplanter disclosed in Patent Document 1 is configured to move the scraper from a position outside the seedling planting tool into the space between a pair of planting claws by the biasing action of a tension spring. With this configuration, there is a problem that it is difficult to obtain sufficient tracking ability for the scraper to follow the seedling planting tool when the seedling planting tool rises quickly due to a high lifting speed.

[0008] In addition, according to the configuration disclosed in Patent Document 2, the drive for moving the scraper relative to the seedling planting tool must be taken out of the planting transmission case constituting the drive system so that the operation of the scraper is synchronized with the lifting and lowering operation of the seedling planting tool. This causes a problem that the drive mechanism for operating the scraper becomes complicated.

[0009] The present invention has been made in consideration of the above-mentioned problems, and relates to a cleaning device for removing soil and the like that has adhered to seedling planting tools. The object of the present invention is to provide a seedling transplanter that has a relatively simple configuration, can obtain good tracking ability with respect to the seedling planting tools that move up and down, and can perform accurate operations synchronized with the operation of the seedling planting tools. [Means for solving the problem]

[0010] The seedling transplanter of the present invention is a seedling transplanter equipped with a seedling planting device having a seedling planting tool that plants seedlings in a field by raising and lowering, and is equipped with a cleaning device having a cleaning body that acts on the seedling planting tool and removes soil and the like adhering to the seedling planting tool with the cleaning body, and an operating member that acts on the cleaning device in conjunction with the raising operation of the seedling planting tool, thereby operating the cleaning device so that the cleaning body acts on the seedling planting tool.

[0011] In the seedling transplanter of the present invention, the operating member moves the cleaning body from a retracted position to a cleaning position where it acts on the seedling planting tool in response to the raising operation of the seedling planting tool.

[0012] The seedling transplanter of the present invention is a seedling transplanter comprising a running body on which the seedling planting device is mounted, the seedling planting tool is arranged to move up and down relative to the running body, and the cleaning device is configured to move the cleaning body forward and backward relative to the seedling planting tool from one side in a direction perpendicular to the opening and closing direction of the seedling planting tool in a plan view.

[0013] The seedling transplanter according to the present invention is such that the cleaning device has a roller that receives the action of the operating member on its outer circumferential surface.

[0014] The seedling transplanter of the present invention is a seedling transplanter in which the cleaning device has, as the cleaning body, an inner cleaning body acting on the inside of the seedling planting tool and an outer cleaning body acting on the outside of the seedling planting tool. Effect of the Invention

[0015] According to the present invention, a cleaning device for removing soil and the like adhering to seedling planting tools has a relatively simple configuration that can provide good tracking of the seedling planting tools as they rise and fall, and can perform accurate operations synchronized with the operation of the seedling planting tools. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a left side view showing an overall configuration of a seedling transplanter according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a plan view showing the overall configuration of a seedling transplanter according to an embodiment of the present invention. [Diagram 3] FIG. 1 is a left side view showing the configuration of a seedling transplanting device according to one embodiment of the present invention. [Figure 4] FIG. 2 is a rear view showing the configuration of the seedling transplanting device according to one embodiment of the present invention. [Diagram 5] 1 is a perspective view showing a hole opening device and a scraper device in a standby state according to an embodiment of the present invention, and the configuration of the surrounding area. FIG. [Figure 6] FIG. 2 is a left side view showing the configuration of the hole opening device and the scraper device in a standby state according to the embodiment of the present invention, as well as the surrounding area. [Figure 7] 1 is a rear view showing a hole opening device and a scraper device in a standby state according to an embodiment of the present invention, and the configuration of the surrounding area. FIG. [Figure 8] FIG. 2 is a right side view showing the scraper device and its surrounding configuration in a standby state according to an embodiment of the present invention. [Figure 9] FIG. 2 is a left side view showing the configuration of the hole opening device and the scraper device in a rotation end state according to one embodiment of the present invention, as well as the surrounding area. [Figure 10] FIG. 2 is a rear view showing the hole opening device and the scraper device in the rotation end state according to the embodiment of the present invention, and the configuration of the surrounding area. [Figure 11] 5A to 5C are explanatory diagrams of a structure for switching the position of a drive cam according to an embodiment of the present invention. [Figure 12]5A to 5C are explanatory diagrams illustrating the operation of the hole opening device and scraper device according to one embodiment of the present invention. [Figure 13] 5A to 5C are explanatory diagrams illustrating the operation of the hole opening device and scraper device according to one embodiment of the present invention. [Figure 14] 5A to 5C are explanatory diagrams illustrating the operation of the hole opening device and scraper device according to one embodiment of the present invention. [Figure 15] 5A to 5C are explanatory diagrams illustrating the operation of the hole opening device and scraper device according to one embodiment of the present invention. [Figure 16] 5A to 5C are explanatory diagrams illustrating the operation of the hole opening device and scraper device according to one embodiment of the present invention. [Figure 17] FIG. 11 is a perspective view showing a hole opening device and a scraper device in a standby state according to another embodiment of the present invention, as well as the configuration of the surroundings. [Figure 18] FIG. 11 is a left side view showing a hole opening device and a scraper device in a standby state according to another embodiment of the present invention, as well as the configuration of the surroundings. [Figure 19] FIG. 11 is a rear view showing a hole opening device and a scraper device in a standby state according to another embodiment of the present invention, as well as the configuration of the surroundings. [Figure 20] FIG. 11 is a left side view showing a hole opening device and a scraper device in a rotation end state according to another embodiment of the present invention, and the configuration of the surroundings. [Figure 21] FIG. 11 is a rear view showing a hole opening device and a scraper device in a rotation end state according to another embodiment of the present invention, and the configuration of the surroundings. [Figure 22] FIG. 11 is a right side view showing a scraper device according to another embodiment of the present invention and a part of its peripheral configuration. [Diagram 23] FIG. 11 is a rear perspective view showing a configuration of a drive cam according to another embodiment of the present invention. [Figure 24] 10A to 10C are diagrams illustrating the operation of a hole opening device and a scraper device according to another embodiment of the present invention. [Diagram 25] 10A to 10C are diagrams illustrating the operation of a hole opening device and a scraper device according to another embodiment of the present invention. [Figure 26] 10A to 10C are diagrams illustrating the operation of a hole opening device and a scraper device according to another embodiment of the present invention. [Figure 27] 10A to 10C are diagrams illustrating the operation of a hole opening device and a scraper device according to another embodiment of the present invention. [Figure 28] 10A to 10C are diagrams illustrating the operation of a hole opening device and a scraper device according to another embodiment of the present invention. [Figure 29] 10A to 10C are diagrams illustrating the operation of a hole opening device and a scraper device according to another embodiment of the present invention. [Diagram 30] FIG. 2 is a front view showing a schematic diagram of a horizontal control mechanism of an aircraft according to an embodiment of the present invention. [Diagram 31] FIG. 2 is a right rear perspective view showing a horizontal control mechanism and its operating section for the aircraft according to one embodiment of the present invention. [Diagram 32] FIG. 2 is a right rear perspective view showing a weight for horizontal control and an operating member for the weight according to one embodiment of the present invention. [Diagram 33] FIG. 2 is a right rear perspective view showing the configuration of a horizontal control operation unit according to one embodiment of the present invention. [Diagram 34] FIG. 4 is a partial rear cross-sectional view showing the configuration of a horizontal control operation unit according to one embodiment of the present invention. [Diagram 35] FIG. 4 is a right side view showing the configuration of a horizontal control operation unit according to one embodiment of the present invention. [Diagram 36] 5A to 5C are diagrams illustrating the operation of a horizontal control operation unit according to one embodiment of the present invention. [Figure 37] FIG. 13 is a right rear perspective view showing an engagement state of a locking arm with a horizontal control weight and a pivot arm according to one embodiment of the present invention. [Figure 38] A rear view showing the scraper structure of the soil cover wheel in one embodiment of the present invention. [Figure 39] FIG. 2 is a left rear perspective view showing the scraper structure of the soil cover wheel according to one embodiment of the present invention. [Diagram 40] 1 is a left side view, partially in section, showing the scraper structure of a soil cover wheel according to one embodiment of the present invention. FIG. [Diagram 41] FIG. 2 is an upper perspective view showing the scraper structure of a soil cover wheel according to one embodiment of the present invention. [Diagram 42]1 is a top view showing a load adjustment structure for a scraper of a soil cover wheel according to one embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention aims to improve the operability and accuracy of the cleaning operation of the cleaning device in a seedling transplanter equipped with a cleaning device for removing soil and the like attached to the seedling planting tool by providing an operating member that operates the cleaning device in conjunction with the raising operation of the seedling planting tool. Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] The configuration of the seedling transplanter 1 according to this embodiment will be described. In the following description, the left side in Fig. 1 is the front of the seedling transplanter 1, and the left side (lower side in Fig. 2) and right side (upper side in Fig. 2) facing the front of the seedling transplanter 1 are the left side and right side of the seedling transplanter 1, respectively.

[0019] As shown in Figures 1 and 2, the seedling transplanter 1 is a walk-behind seedling transplanter that is driven and operated by a walking operator and moves forward to successively plant seedlings 9 in ridges 11 in a farm field 10. The seedling transplanter 1 is used for successively transplanting seedlings 9 of vegetables such as cabbage, onion, tomato, green onion, Chinese chive, beans, broccoli, etc., into the ridges 11.

[0020] The seedling transplanter 1 comprises a running body 2 which constitutes the running section, a seedling planting device 3 which is provided on the rear side of the running body 2 and which constitutes the transplanting section, a seedling supply section 4 which is provided above the seedling planting device 3, and a control section 5 which is provided behind the seedling supply section 4.

[0021] The traveling machine body 2 has a machine body frame 6, left and right front wheels 7, and left and right rear wheels 8. The machine body frame 6 is supported on a field 10 by the left and right front wheels 7 and the left and right rear wheels 8. The machine body frame 6 is composed of a pair of left and right frame plates 6a with the plate thickness direction being in the left-right direction, and a plurality of frame members including a frame installed between these frame plates 6a.

[0022] An engine 12 serving as a drive source is mounted on the upper front side of the vehicle frame 6. The engine 12 is supported by predetermined support members on the upper front sides of the left and right frame plates 6a. The engine 12 is, for example, a diesel engine, and is oriented with the axial direction of the output shaft aligned in the left-right direction.

[0023] A fuel tank 13 is provided above the engine 12. The engine 12 and fuel tank 13 are covered from above by a bonnet 14 provided above the fuel tank 13. A transmission case 15 is provided behind the engine 12 on the vehicle frame 6, and has a built-in power transmission mechanism including a group of gears, a clutch, a brake, etc.

[0024] A front wheel support shaft 16 is horizontally supported on the front ends of the left and right frame plates 6a with its axial direction being the left-right direction. The front wheel support shaft 16 penetrates the front ends of the left and right frame plates 6a and extends outwardly to the left and right from the left and right frame plates 6a. A front wheel 7 is rotatably supported on both ends of the front wheel support shaft 16 via a front wheel support arm 17. The front wheel support arm 17 is a linear frame part and extends downward from the end of the front wheel support shaft 16 so as to form a right angle with the front wheel support shaft 16. The front wheel 7 is supported on the lower end of the front wheel support arm 17 by a support shaft 17a with its axial direction being the left-right direction.

[0025] The left and right rear wheels 8 are supported by a chain case 18 provided on the left and right outer sides of the transmission case 15. The chain case 18 has a longitudinal shape, and one end in the longitudinal direction is connected to the left and right outer ends of a cylindrical drive shaft case 19 that extends linearly outwardly from the transmission case 15. A rear wheel drive shaft 20 is provided within the drive shaft case 19, extending outwardly from the transmission case 15 with the left and right direction as its axial direction.

[0026] An axle 21 that supports the rear wheel 8 is rotatably provided at the other longitudinal end of the chain case 18. The axle 21 protrudes inwardly to the left and right from the chain case 18. A chain transmission mechanism for transmitting the rotational power of the rear wheel drive shaft 20 to the axle 21 is provided inside the chain case 18.

[0027] With this configuration, power from the engine 12 is transmitted from the transmission case 15 to the rear wheel drive shaft 20 in the drive shaft case 19, and then transmitted to the axle 21 via the chain transmission mechanism in the chain case 18. The rotational driving force of the axle 21 drives and rotates the rear wheel 8.

[0028] A handle frame 25 is provided on the rear side of the transmission case 15 as a handle member. The handle frame 25 is made of a pipe-shaped member having a predetermined bent shape so as to be substantially U-shaped with the front side open in a plan view. The handle frame 25 has left and right front-rear extensions 25a and a left-right extension 25b between the rear ends of the left and right front-rear extensions 25a as the parts forming the substantially U-shaped plan view shape. The handle frame 25 is supported by the transmission case 15 in such a manner that the front ends of the left and right front-rear extensions 25a sandwich the rear upper end of the transmission case 15 from the left and right, and extends horizontally rearward from the transmission case 15.

[0029] A connecting plate 26 forming a horizontal surface portion is installed between the front-rear middle portions of the left and right front-rear extension portions 25a of the handle frame 25. A control unit 5 is configured at the rear of the handle frame 25 by arranging various operating tools such as a machine body up-down / planting clutch lever 27, a main clutch lever 28, a handle height adjustment lever 29, an accelerator lever, a side clutch lever, etc. In addition, a main speed change lever 30 extends rearward and upward from the transmission case 15. The control unit 5 is used to drive and operate the traveling body 2 and the seedling planting device 3.

[0030] A pair of left and right rear frames 31 are provided on the rear side of the transmission case 15. The rear frames 31 are made of pipe-shaped members having a predetermined bent shape, are arranged in an upwardly slanted manner toward the rear in a side view, and extend in the front-rear direction in a plan view. The front end of the rear frames 31 is fixedly supported to the lower rear end of the transmission case 15 via a predetermined support member, and the rear end is fixedly supported to the connecting plate 26.

[0031] The seedling supply unit 4 is provided at a position that is inside the handle frame 25 in a plan view. The seedling supply unit 4 is configured to continuously supply seedlings 9 to the seedling planting device 3 at a predetermined timing. Seedling carriers 32 are provided on both the left and right outsides of the handle frame 25. Each seedling carrier 32 is supported by a seedling carrier support frame 33 that is erected while being supported by the front-rear extension parts 25a on the left and right sides of the handle frame 25.

[0032] The seedling planting device 3 is provided behind the transmission case 15 and below the seedling supply unit 4, between the left and right rear frames 31. As shown in Figs. 3 and 4, the seedling planting device 3 has a hole opening device 40 as a seedling planting tool that plants seedlings 9 in the field 10 by lifting and lowering, and a lifting mechanism 41 that lifts and lowers the hole opening device 40. The seedling planting device 3 has, as components forming the lifting mechanism 41, a rotary case 42 that is a drive unit arranged on one side (left side) of the hole opening device 40 in the left-right direction, a lifting guide 43 that is a guide unit arranged on the other side (right side) of the hole opening device 40 in the left-right direction, and an arm 44 connected to the rotary case 42.

[0033] The hole opener 40 sends the seedlings 9 from the seedling supply section 4 to the furrows 11 by lifting and lowering, and plants them. The hole opener 40 has a pair of planting claws 45, which are front and rear planting bodies, and is configured to be able to open and close in the front and rear direction by the pair of planting claws 45, so that when closed, it forms a hollow cup part with a sharp tip on the lower side. The internal space of the hole opener 40 in the closed state temporarily becomes a space to accommodate the seedlings 9. Each planting claw 45 has a mating surface 45a with the other planting claw 45. The mating surface 45a is formed as a surface along a plane so as to follow a straight line in a side view, and becomes the dividing surface of the hole opener 40 in the closed state.

[0034] The hole opener 40 is provided so as to move up and down while tracing a fixed trajectory by a lifting mechanism 41. The hole opener 40 is configured to receive the seedlings 9 from the seedling supply unit 4 at the upper end position of the lifting motion, to move down and enter the ridges 11 of the field 10, to open a pair of planting claws 45 at the lower end position of the lifting motion to release the seedlings 9 into the planting holes formed in the ridges 11, and to plant the seedlings 9 in the ridges 11.

[0035] The rotary case 42 has a generally elongated elliptical shape in a side view and a flat shape with its thickness in the left-right direction. The rotary case 42 has a fulcrum shaft 46 protruding outwardly to the left and right (left) from one end of the longitudinal direction, and is supported rotatably on the fulcrum shaft 46. The fulcrum shaft 46 is an axis whose axial direction is the left-right direction, and is provided in a state fixed to the left rear frame 31 via a support member.

[0036] The rotary case 42 rotates around the fulcrum shaft 46 by the power extracted by the planting output shaft 47 from the transmission case 15. The planting output shaft 47 is provided at the rear upper end of the transmission case 15 with the left-right direction as the axial direction, and both the left and right sides protrude from the transmission case 15. The rotary case 42 rotates by receiving the rotational power of the planting output shaft 47 transmitted by the chain transmission mechanism 50.

[0037] The chain transmission mechanism 50 is provided on the left side of the transmission case 15 and the rotary case 42 in the left-right direction. The chain transmission mechanism 50 has a drive sprocket 51 fixed to the portion of the planting output shaft 47 that protrudes leftward from the transmission case 15, a driven sprocket 52 provided on the left side of the rotary case 42, and an endless chain 53 wound around these sprockets.

[0038] The driven sprocket 52 is supported by the fulcrum shaft 46 and is rotatable relative to the fulcrum shaft 46. The driven sprocket 52 is fixed to the rotary case 42 at multiple locations by bolts 54 and rotates integrally with the rotary case 42 around the fulcrum shaft 46. The bolts 54 pass through the driven sprocket 52 and are screwed into the rotary case 42. The fixing portions using the bolts 54 are provided at four locations at equal angular intervals around the axis of the fulcrum shaft 46.

[0039] On the other hand, the rotational power of the planting output shaft 47 is transmitted as the driving force of the rotating table 90 of the seedling supplying unit 4 from the part protruding to the right from the transmission case 15 by a power transmission mechanism such as a belt transmission mechanism. With this configuration, the seedling planting device 3 and the seedling supplying unit 4 are configured to drive synchronously.

[0040] A first gear 56 fitted onto the fulcrum shaft 46, a second gear 57 meshed with the first gear 56, and a third gear 58 arranged at the other end of the rotary case 42 in the longitudinal direction and meshed with the second gear 57 are provided within the rotary case 42. The second gear 57 is rotatably supported at the middle part of the rotary case 42 in the longitudinal direction. The third gear 58 is fitted onto an output shaft 59 provided at the other end of the rotary case 42 in the longitudinal direction. The output shaft 59 is provided to be rotatable relative to the rotary case 42 via a bearing or the like, and the right end protrudes rightward from the rotary case 42.

[0041] The arm 44 is a bent plate-like member having a substantially "L"-shaped cross section and extends linearly. The arm 44 has a body surface portion 44a with a plate thickness direction in the left-right direction as a portion forming a substantially "L"-shaped cross section, and a bent surface portion 44b bent from the front side of the body surface portion 44a to the right in the state shown in FIG. 3 and with a plate thickness direction in the substantially front-rear direction. The arm 44 has one end in the longitudinal direction fixed to a portion of the output shaft 59 protruding to the right from the rotary case 42. The output shaft 59 penetrates the body surface portion 44a of the arm 44 and is fastened and fixed to the arm 44 by a nut 60 or the like screwed to the right end of the output shaft 59. The arm 44 rotates relative to the rotary case 42 together with the output shaft 59 as the output shaft 59 rotates relative to the rotary case 42.

[0042] During the planting operation by the seedling planting device 3, the rotary case 42 rotates clockwise (rightward) around the fulcrum shaft 46 as viewed from the left side (see arrow A1 in FIG. 3). In this embodiment, the number of teeth of the first gear 56 is twice the number of teeth of the third gear 58, and when the rotary case 42 rotates once around the fulcrum shaft 46, the arm 44 rotates twice relative to the rotary case 42 around the output shaft 59 in the direction opposite to the rotation direction of the rotary case 42.

[0043] One end (left end) of a connecting shaft 61, whose axial direction is the left-right direction, is fixed to the other end of the arm 44. The connecting shaft 61 extends to the right from the other end of the arm 44. A planting claw support 62 that supports a pair of planting claws 45 in the hole opening device 40 is supported on the connecting shaft 61.

[0044] The planting claw support 62 has a main body support portion 63, a cup portion 64, and a claw support portion 65. The main body support portion 63 has a pair of left and right support plates 66 that form a roughly "T" shape lying on their sides in a side view. The pair of support plates 66 have the same or roughly the same shape, are arranged so as to overlap each other in a side view, and are connected to each other by a connecting member (not shown) or the like that is installed between them.

[0045] The support plate 66 has a substantially rectangular base 66a with its longitudinal direction extending substantially in the front-to-rear direction as a portion forming a substantially "T"-shaped shape in side view, and an upper protruding portion 66b and a lower protruding portion 66c protruding upward and downward from the front end portion of the base 66a. The pair of support plates 66 are supported rotatably relative to the connecting shaft 61 with the connecting shaft 61 passing through the lower protruding portion 66c. An opening / closing cam 67 is fixed to the connecting shaft 61 in a portion between the left and right support plates 66.

[0046] The cup portion 64 is a portion having a funnel shape (inverted truncated cone shape) that is open at the top and bottom, and is provided on the rear side of the base portion 66a of the pair of support plates 66. The hole opener 40 is provided on the underside of the cup portion 64, and the cup portion 64 is provided so that its internal space communicates with the inside of the hole opener 40. The cup portion 64 is a portion that makes it easier for seedlings to enter the hole opener 40, and receives seedlings supplied from the seedling supply portion 4 and guides them into the hole opener 40.

[0047] The claw support portion 65 is provided on the underside of the cup portion 64, and has a pivot support portion 68 that pivotally supports the front and rear planting claws 45 as a protruding portion from the lower position of the cup portion 64 to both the front and rear sides. The pivot support portion 68 has a pair of left and right support plate portions 68a with the plate thickness direction being the left-right direction. The front and rear planting claws 45 are rotatably supported by the front and rear pivot support portions 68 by claw fulcrum shafts 69 with the left-right direction as the axial direction.

[0048] The front and rear planting claws 45 each have left and right support wall portions 72 formed at positions corresponding to the pivot support portion 68 via a plate-shaped support upper surface portion 71 formed in a flange shape so as to protrude from the upper opening end to the front or rear. The left and right support wall portions 72 are located on the left and right outer sides of the left and right support plate portions 68a, respectively. The planting claws 45 are pivotally supported on the pivot support portion 68 by a claw fulcrum shaft 69 that penetrates the left and right support wall portions 72 and the support plate portion 68a. The front and rear claw fulcrum shafts 69 are provided in positions that are symmetrical about a straight line (crack line) along which the mating surfaces of the front and rear planting claws 45 in a closed state are aligned in a side view.

[0049] The hole opener 40 opens and closes the front and rear planting claws 45 from the tip side by rotating the front and rear planting claws 45 about the axial support part 68 around the claw fulcrum shaft 69. Regarding the opening and closing operation of the hole opener 40, the hole opener 40 is biased in the closing direction by the coil-shaped return spring 73 arranged on both the left and right sides of the cup part 64.

[0050] Each planting claw 45 has left and right locking plate portions 74 as portions that receive the locking of one end side (lower end side) of the return spring 73. The locking plate portions 74 are plate-shaped portions with the plate thickness direction being the left-right direction, and are provided on the opposite side of the support wall portion 72 from the support upper surface portion 71, that is, on the side of the opposing planting claw 45 in each planting claw 45. The locking plate portions 74 are located on both the left and right sides of the lower part of the cup portion 64.

[0051] The front and rear planting claws 45 are connected and supported by a pivot shaft 75 that passes through the overlapping locking plate parts 74, with parts of the locking plate parts 74 overlapping each other. One end of the return spring 73 is engaged with the pivot shaft 75 via a locking pin 76 that locks one end of the return spring 73. The other end (upper end) of each return spring 73 is engaged with the peripheral wall part that forms the upper opening end of the cup part 64 via a locking member or the like (not shown). The return spring 73 urges the hole opening device 40 in the direction of closing by lifting the overlapping parts of the locking plate parts 74 of the front and rear planting claws 45.

[0052] With the above-mentioned configuration, the opening and closing mechanism of the hole opener 40 is configured such that the front and rear upper end sides of the front and rear planting claws 45 are rotatably supported by the claw fulcrum shaft 69, and the front and rear central parts of the upper end sides are biased in the direction of closing the hole opener 40 by the return spring 73 via the pivot shaft 75. The hole opener 40 is configured to store and support seedlings in the closed state with the front and rear planting claws 45 aligned, and to drop the seedlings in the open state with the front and rear planting claws 45 separated from each other.

[0053] One end (rear end) of the abutment arm 80 is pivoted to the claw fulcrum shaft 69 that supports the front planting claw 45. The abutment arm 80 is located between a pair of support plate parts 68a of the front shaft support part 68 in the left-right direction. The abutment arm 80 has a pair of elongated arm plates 80a on the left and right, and the front claw fulcrum shaft 69 passes through these arm plates 80a. Between the other ends (front ends) of the left and right arm plates 80a, an abutment roller 81 is provided with the left-right direction as the rotation axis direction. The abutment arm 80 is provided so that the abutment roller 81 abuts against the outer circumferential surface of the opening / closing cam 67.

[0054] Between the abutment arm 80 and the support upper surface 71 of the front planting claw 45, a claw opening / closing amount adjustment mechanism 83 for adjusting the opening / closing amount of the hole opening device 40 is provided. The claw opening / closing amount adjustment mechanism 83 has an adjustment bolt 84. The adjustment bolt 84 penetrates the support upper surface 71 from the bottom and a cylindrical screw penetration portion 85 provided between the left and right arm plates 80a at the longitudinal intermediate portion of the abutment arm 80, and receives a nut 89 screwed at the protruding portion to the top. The claw opening / closing amount adjustment mechanism 83 is configured to adjust the interval between the support upper surface 71 and the abutment arm 80 by rotating the adjustment bolt 84, and adjust the rotation amount of the planting claw 45, i.e., the opening amount of the hole opening device 40.

[0055] With regard to the lifting and lowering operation of the hole opening device 40, the planting claw support 62 supporting the hole opening device 40 is guided by the lifting guide 43 via a roller support shaft 86 and a guide roller 87. The roller support shaft 86 has an axial direction in the left-right direction, penetrates the upper protruding portion 66b of the left and right support plates 66, and extends rightward from the right support plate 66. A guide roller 87 is supported rotatably on the right end of the roller support shaft 86.

[0056] The lift guide 43 is a linear member that extends substantially vertically and forms a guide groove 88 with the left side open, and is provided in a state of being fixed to the right rear frame 31 and the right front-rear extension part 25a of the handle frame 25 via a support member at a position right in front of the hole opening tool 40. The lift guide 43 has a front part 43a, a rear part 43b, and a right side part 43c as parts that form the guide groove 88, and these sides form a substantially "U"-shaped cross section. The lift guide 43 has an upper part 43d and a lower part 43e that close both the upper and lower ends of the guide groove 88. The lift guide 43 guides the movement of the guide roller 87 accompanying the lifting and lowering operation of the hole opening tool 40 with the guide roller 87 fitted in the guide groove 88.

[0057] In the above configuration, the hole opener 40, which is biased in the closing direction by the left and right return springs 73, is restricted in rotation by the abutment arm 80 abutting the abutment roller 81 against the opening and closing cam 67. The hole opener 40 opens and closes by rotating the front and rear planting claws 45 under the action of the opening and closing cam 67, which rotates with the rotation of the rotary case 42. The hole opener 40 rotates the front and rear planting claws 45 in the opening direction against the biasing force of the return spring 73. Here, the rear planting claw 45 rotates in conjunction with the rotation of the front planting claw 45 around the claw fulcrum axis 69 accompanying the rotation of the abutment arm 80 due to the connection structure with the front planting claw 45 by the pivot shaft 75 that engages one end side of the return spring 73.

[0058] The hole opener 40 is located at the upper end in a closed state, and receives the seedlings 9 from the seedling supply unit 4 through the cup portion 64. The hole opener 40 that has received the seedlings 9 is pulled downward through the arm 44 with the rotation of the rotary case 42, and is guided by the lift guide 43, and descends together with the planting claw support 62. When the hole opener 40 reaches the lower end, the contact arm 80 rotates due to the action of the opening and closing cam 67, and the front and rear planting claws 45 rotate around the claw fulcrum shaft 69 against the biasing force of the return spring 73 with the rotation of the contact arm 80, and the hole opener 40 is opened. As a result, the seedlings 9 in the hole opener 40 are dropped and released onto the furrow 11. After that, the hole opener 40 rises with the rotation of the rotary case 42, and at the upper end, it is closed by the action of the opening and closing cam 67 and the biasing force of the return spring 73. The hole opening device 40 moves up and down while tracing a vertically long, substantially elliptical path with the path of its descending motion being located forward of the path of its ascending motion in a side view.

[0059] As shown in Figures 1 and 2, the seedling supplying section 4 has a disk-shaped rotating table 90 that is horizontally arranged so as to form a circle in a plan view. The rotating table 90 has a rotating shaft 91 that runs along the up-down direction at the center of the circle in the plan view. The rotating table 90 is configured to receive power taken out from the transmission case 15 and to be intermittently rotated around the rotating shaft 91.

[0060] A rotating base frame 92 is provided below the rotating base 90. The rotating base frame 92 has a circular shape in a plan view and is configured with a diameter slightly smaller than that of the rotating base 90. The rotating base frame 92 forms a peripheral wall that surrounds the space below the rotating base 90 in a circular shape along the outer shape of the rotating base 90, and is provided in a fixed state on the connecting plate 26.

[0061] The rotating table 90 is provided with a plurality of cylindrical pot receiving portions 93 that are open on the top and have a bottom plate. The pot receiving portions 93 are provided so that the central axis direction of the cylindrical outer shape is the up-down direction, and most of the upper side protrudes from the upper surface of the rotating table 90. In this embodiment, eight pot receiving portions 93 are disposed at equal angular intervals in the circumferential direction along the circumferential shape of the rotating table 90, which is the outer shape in a plan view.

[0062] A seedling transport pot 94 is inserted into each pot receiving portion 93. The seedling transport pot 94 is a cylindrical member with both ends open, and has a horn-like or funnel-like shape with a gradually increasing diameter from the bottom to the top. When inserted into the pot receiving portion 93, the upper portion of the seedling transport pot 94 is exposed upward from the upper end of the pot receiving portion 93. The worker throws or inserts the seedlings 9 taken out from the left and right seedling carriers 32 into the seedling transport pots 94 one by one.

[0063] In the seedling supplying section 4 having the above-mentioned configuration, when the hole opener 40 of the seedling planting device 3 reaches the raised end position, the bottom plate of the pot receiving section 93 located directly above the hole opener 40 is opened. As a result, the seedlings 9 in the seedling transport pot 94 drop and become contained in the hole opener 40. In this manner, the seedlings 9 are supplied from the seedling supplying section 4 to the hole opener 40. The hole opener 40 that has received the seedlings 9 descends and plants the seedlings in the ridges 11 of the field 10.

[0064] A pair of left and right soil cover wheels 95 are provided behind the seedling planting device 3. The soil cover wheels 95 are provided in a state in which they are supported by a soil cover wheel support frame 96. The soil cover wheel support frame 96 is configured in a frame shape made of rod-shaped members so as to form a substantially "U" shape with the front side open in a plan view. The soil cover wheel support frame 96 is provided so as to be vertically rotatable by supporting the left and right front ends of the soil cover wheel support frame 96 rotatably with the left and right direction as the rotation axis direction relative to brackets 97 fixed to the front and rear middle parts of the left and right rear frames 31, respectively.

[0065] The soil covering wheels 95 are supported so that their outer peripheral surfaces are rotatably supported as acting surfaces for the ridges 11 of the field 10. The pair of soil covering wheels 95 are inclined so that their lower ends approach each other relative to their upper ends, and are arranged to form a substantial "V" shape when viewed from behind.

[0066] The seedling transplanter 1 having the above-mentioned configuration, while traveling, puts seedlings 9 into the hole opening device 40 from the seedling supply unit 4, and lowers the hole opening device 40 by the operation of the lifting mechanism 41, inserts the tip of the hole opening device 40 into the ridge 11, and opens the hole opening device 40, thereby transplanting the seedlings 9. The seedlings 9 are transplanted continuously at a predetermined planting interval (between plants). The part where the seedlings 9 are planted by the seedling planting device 3 is suppressed by the action of a pair of left and right soil covering wheels 95 immediately after planting. The seedling transplanter 1 according to this embodiment is configured as a one-ridge, one-row planting type in which one row is planted in one ridge 11. However, the present invention is also applicable to a seedling transplanter configured as a multiple-row planting type in which seedlings are planted in multiple rows simultaneously.

[0067] The seedling transplanter 1 having the above-mentioned configuration is provided with a scraper device 100 as a cleaning device for removing soil, mud, etc. adhering to the hole opener 40 in the seedling planting device 3. The scraper device 100 is provided so as to rotate in conjunction with the lifting and lowering operation of the hole opener 40 and act on the hole opener 40. The seedling transplanter 1 is provided with a drive cam 101 as an operating member for operating the scraper device 100, which acts on the scraper device 100 in conjunction with the lifting and lowering operation of the hole opener 40.

[0068] The scraper device 100 and its operating mechanism will be described with reference to Figures 5 to 11. The scraper device 100 has a scraper 102 as a cleaning body that acts on the hole opening device 40, and removes soil and the like adhering to the hole opening device 40 by scraping it off with the scraper 102.

[0069] Figures 5 to 8 show the scraper device 100 in a standby position (hereinafter referred to as the "standby state"). The scraper device 100 is actuated by the action of the drive cam 101 in the standby state, and is set up to periodically perform a series of actions in which the scraper device 100 acts on the hole opener 40 to reach a rotation end position (hereinafter referred to as the "rotation end position") and then returns to the standby position in conjunction with the lifting and lowering of the hole opener 40. Figures 9 and 10 show the scraper device 100 in a rotation end position (hereinafter referred to as the "rotation end state"). The standby state is used as the basis for the explanation of the scraper device 100.

[0070] The scraper device 100 has, as scrapers 102, an inner scraper 102A acting on the inside of a pair of planting claws 45, a front scraper 102B acting on the outside of the front planting claw 45, and a rear scraper 102C acting on the outside of the rear planting claw 45. Of these three scrapers 102, the inner scraper 102A is an example of an inner cleaning body acting on the inside of the hole opening device 40, and the front scraper 102B and the rear scraper 102C are examples of outer cleaning bodies acting on the outside of the hole opening device 40.

[0071] The scraper device 100 has a base plate 105, a scraper arm 107 fixed to the base plate 105 and supporting each scraper 102, a driven roller 108 fixed to the base plate 105, and a shaft support part 109 that shaft supports the base plate 105. The scraper device 100 is supported via a scraper support part 110 on the rear end part of the left rear frame 31 (see FIGS. 1 and 6 ) whose front end part is fixed to the transmission case 15.

[0072] The scraper device 100 is provided to be rotatable within a predetermined angle range around a rotation axis C1 with respect to the scraper support part 110 (see Figs. 6 and 7). The rotation axis C1 is inclined downward toward the front in a side view, and has an axial direction along the front-rear direction in a plan view.

[0073] The scraper support part 110 has an upper bracket 111 and a lower bracket 112, both of which are channel steel-like members having a generally U-shaped cross section. These brackets are fixed to each other by bolts 113 with the upper bracket 111 positioned on the left side and the lower bracket 112 positioned on the right side, with their bottom surfaces in the channel shape facing each other. The bolt 113 passes through the bottom surface of the upper bracket 111 and screws into a nut part 114 provided on the inside (right side) of the bottom surface of the lower bracket 112. The fixing parts using the bolt 113 are provided at two locations, top and bottom.

[0074] The lower bracket 112 has a longitudinal direction perpendicular to the axial direction of the pivot shaft C1 in a side view and vertically aligned in a rear view. The upper bracket 111 extends obliquely upward and forward from an upper portion of the lower bracket 112 in a side view. The upper bracket 111 is fixed to the rear end portion of the left rear frame 31 at its upper portion. The upper bracket 111 has a notched recess 111a formed on the left side of the upper portion of the front and rear wall portions, the recess 111a having a curved shape that follows the outer peripheral shape of the rear frame 31. The upper bracket 111 is fixed to the rear frame 31 by welding or the like in such a manner that the rear frame 31 is fitted into the recess 111a of the front and rear wall portions.

[0075] A scraper support shaft 115 is fixed to the lower end of the lower bracket 112. The scraper support shaft 115 is a straight rod-shaped member, and is fixed to the lower bracket 112 by welding or the like in a state where it fits into a notched recess formed on the right side of the lower part of the front and rear wall surfaces of the lower bracket 112. The scraper support shaft 115 has its central axis aligned with the rotation axis C1, and its front part extends forward from the lower bracket 112. A shaft support part 109 is provided on the portion of the scraper support shaft 115 extending forward from the lower bracket 112.

[0076] The shaft support part 109 is composed of a cylindrical bearing member through which the front part of the scraper support shaft 115 penetrates. The shaft support part 109 has an inner peripheral part into which the scraper support shaft 115 is inserted and which is fixed to the scraper support shaft 115, and an outer peripheral cylindrical part 109a which is a part that can rotate relatively to the inner peripheral part and forms the outer peripheral surface of the shaft support part 109.

[0077] The base plate 105 is substantially entirely a flat plate having a predetermined shape, and the plate surface is inclined downward toward the front along the axial direction of the rotation axis C1 in a side view, and is inclined downward from the left-right inner side (right side) to the left-right outer side (left side) in a rear view. The base plate 105 is located on the lower right side of the pivot support part 109, and is fixed to the outer circumferential cylinder part 109a of the pivot support part 109 by welding or the like.

[0078] The base plate 105 has a rear portion to which the pivot support 109 is fixed. A rectangular through opening 105a is formed in the base plate 105 at the portion to which the pivot support 109 is fixed (see FIG. 8). The opening 105a has substantially the same dimensions as the outer peripheral cylinder 109a in the axial direction of the pivot support 109, and has a dimension shorter than the outer diameter of the pivot support 109 in a direction perpendicular to the axial direction of the pivot support 109 along the plate surface of the base plate 105. The base plate 105 is fixed to the outer peripheral cylinder 109a with the lower right end of the outer peripheral cylinder 109a positioned within the opening 105a.

[0079] With such a support configuration of the base plate 105, the base plate 105 is supported integrally with the outer circumferential cylinder portion 109a of the shaft support portion 109 relative to the scraper support shaft 115 so as to be rotatable about the axis of the scraper support shaft 115 (around the rotation axis C1).

[0080] The base plate 105 has an arm support portion 105b extending downward and to the left from the fixed portion relative to the pivot support portion 109, which serves as the arm support portion 105b supporting the multiple (three) scraper arms 107. The arm support portion 105b is a generally rectangular protruding piece. The scraper arms 107 supporting the respective scrapers 102, the front scraper 102B, the inner scraper 102A, and the rear scraper 102C, are attached to the arm support portion 105b in this order from the front side to the rear side. A scraper 102 is attached to the tip of each scraper arm 107.

[0081] Each scraper arm 107 is made of a narrow plate-like member having a predetermined bent shape, and is fixed to the base plate 105 at two points by bolts 117 with the base end overlapping the underside of the arm support part 105b. The bolts 117 pass through the base plate 105 and the base end of the scraper arm 107, and are screwed into a nut part 118 provided on the back side of the scraper arm 107.

[0082] The two fixing parts of each scraper arm 107 by the bolts 117 are provided at an interval in the longitudinal direction of the base end of the scraper arm 107. The hole part through which the lower bolt 117 passes in the arm support part 105b is an elongated hole 105c along an arc concentric with the circular hole part through which the upper bolt 117 passes. With this configuration, the scraper arm 107 can rotate back and forth with respect to the base plate 105 within the range of the length of the elongated hole 105c around the fixing part by the upper bolt 117, and the fixing angle of the scraper arm 107 with respect to the base plate 105 can be adjusted. By adjusting the fixing angle of the scraper arm 107, the front-rear position of the scraper 102 can be adjusted.

[0083] The three scraper arms 107 extend downward from the arm support portion 105b of the base plate 105 and support the scraper 102 at positions where they do not interfere with each other. The scraper 102 is a plate-like member made of an elastic material such as rubber, sponge, or plastic. In this embodiment, the scraper 102 has a structure of two overlapping rubber plates.

[0084] The three scrapers 102 are provided so that their plate surfaces are approximately parallel to the plate surface of the base plate 105, and have approximately the same inclination. When viewed in the axial direction of the rotation shaft C1, the front scraper 102B and the rear scraper 102C are provided at positions overlapping each other, and the inner scraper 102A is located one step below these scrapers 102.

[0085] Each scraper 102 is fixed to a scraper attachment part 107a formed at the tip of each scraper arm 107 as a surface part parallel to the scraper 102 and bent relative to the main body of the scraper arm 107. The scraper attachment part 107a is a longitudinal part whose longitudinal direction is the direction of inclination downward to the left when viewed in the axial direction of the rotation shaft C1. The scraper 102 overlaps the scraper attachment part 107a from below, and is sandwiched between the scraper attachment part 107a and a pressing plate 119 located below the scraper 102.

[0086] The pressing plate 119 is a longitudinal plate-like member, and is provided so that its longitudinal direction is aligned with the longitudinal direction of the scraper mounting portion 107a. The scraper 102 and pressing plate 119 are fastened and fixed to the scraper mounting portion 107a at two locations by two bolts 121 and nuts 122 that penetrate both longitudinal ends of the pressing plate 119. The bolts 121 penetrate the pressing plate 119, the scraper 102, and the scraper mounting portion 107a from below, and are screwed into the nuts 122 located on the upper side of the scraper mounting portion 107a.

[0087] The front scraper 102B and the rear scraper 102C have a generally trapezoidal outer shape, with the upper edge of the outer shape being the part to be clamped by the scraper attachment part 107a and the pressing plate 119, and the majority of the lower side extending in a fin-like shape from the clamped part. The front scraper 102B and the rear scraper 102C have a generally "V" shaped recess on the edge of the lower side, with a slit-like notch 102s in the center, separating the fin-like extension into two parts. This makes the scraper 102 easy to deform elastically.

[0088] The front scraper 102B and the rear scraper 102C are provided so that the lower bottom sides of the approximately trapezoidal outer shape face each other in the front-rear direction. Therefore, in the front scraper 102B, the front part is fixed by the bolt 121, etc., and the majority of the rear side is a fin-shaped extension. In the rear scraper 102C, the rear part is fixed by the bolt 121, etc., and the majority of the front side is a fin-shaped extension. In these scrapers 102, the fin-shaped extension is the part that mainly elastically deforms when it acts on the hole opening device 40.

[0089] The inner scraper 102A has a home plate-like (approximately pentagonal) outer shape with the top side of the outer shape facing the base side (lower side) of the scraper attachment part 107a, and the central part in the width direction, which is approximately the front-to-rear direction, serves as the part to be clamped by the scraper attachment part 107a and the pressing plate 119, with both sides in the width direction extending in a fin-like shape from the clamped part. In the inner scraper 102A, the fin-like extending parts on both sides are the parts that mainly undergo elastic deformation when acting on the hole opening device 40.

[0090] The driven roller 108 is rotatably supported by a roller support portion 105d, which is an extension portion extending forward from the arm support portion 105b of the base plate 105, via a roller support shaft 125. The roller support shaft 125 is a straight rod-shaped member, with its axial direction parallel to the axial direction of the rotation shaft C1 and its axis positioned lower than the axis of the rotation shaft C1. When the scraper device 100 is in the standby state, the left-right position of the axis of the roller support shaft 125 coincides or approximately coincides with the rotation shaft C1.

[0091] The roller support shaft 125 has a rear portion fixed to the underside of the roller support portion 105d by welding or the like, and a front portion extending forward from the roller support portion 105d. A driven roller 108 is provided on the portion of the roller support shaft 125 extending forward from the roller support portion 105d.

[0092] The driven roller 108 is a part that is acted upon by the driving cam 101, and is a roller that receives the abutment of the driving cam 101 on its outer circumferential surface 108a (see FIG. 11). The driven roller 108 is composed of a cylindrical bearing member through which the front part of the roller support shaft 125 penetrates. In this embodiment, the driven roller 108 is composed of two bearings of the same diameter that are journaled on the roller support shaft 125 and connected in the axial direction.

[0093] In the above configuration, the scraper device 100 rotates from a standby state left (counterclockwise) as viewed from the rear about the rotation axis C1 (see arrow D1 in FIG. 10), causing the three scrapers 102 to act on the hole opening device 40. In the scraper device 100, a rotation unit that rotates integrally with the scraper support shaft 115 about the rotation axis C1 is formed by the base plate 105, the three sets of scraper arms 107 and scrapers 102 and driven rollers 108 attached to the base plate 105, and the outer circumferential cylindrical portion 109a of the shaft support portion 109.

[0094] The scraper device 100 is provided so as to be rotatable about the rotation axis C1 within an angle range from a standby position to a rotation end position in which the plate surface of the base plate 105 is aligned vertically and all three scrapers 102 are located to the right of the hole opening device 40 (see FIG. 10). The rotation angle of the scraper device 100 from the standby position to the rotation end position is approximately 45°. However, the magnitude of this rotation angle is not particularly limited.

[0095] A return spring 128 is provided that acts in a direction to return the scraper device 100 to the standby position with respect to the rotational movement of the scraper device 100. The return spring 128 is a coil spring having locking portions at both ends, with the locking portion at one end locked to a fixed-side support pin 131 provided on the scraper support portion 110 side, and the locking portion at the other end locked to a movable-side support pin 132 provided on the rotating unit side. These pins are provided parallel to each other with their axial direction being the front-rear direction.

[0096] The fixed-side support pin 131 is fixed to a support protrusion 112b, which is an extending portion from the lower side of the bottom surface of the lower bracket 112, and protrudes rearward from the support protrusion 112b. The support protrusion 112b is an inclined surface that is inclined to follow the inclination of the base plate 105, and the fixed-side support pin 131 is fixed to the upper side of the support protrusion 112b by welding or the like.

[0097] The movable support pin 132 is provided on a rear bent surface portion 105e of the base plate 105, and is located to the right of the fixed support pin 131. The rear bent surface portion 105e is formed as a portion bent downward with respect to the main body portion on the rear side of the base plate 105, and is a portion whose plate thickness direction is in the front-to-rear direction. The movable support pin 132 is fixed to the rear bent surface portion 105e by welding or the like with its front end portion penetrating the rear bent surface portion 105e, and extends rearward from the rear bent surface portion 105e.

[0098] The return spring 128 is installed between the fixed side support pin 131 and the movable side support pin 132 in the approximately left-right direction (see FIG. 7). The fixed side support pin 131 and the movable side support pin 132 position the scraper support shaft 115 between them in the left-right direction.

[0099] In addition, with regard to the rotational movement of the scraper device 100, a standby position side stopper 135 and a rotation end position stopper 136 are provided between the scraper support portion 110 and the scraper device 100 as stoppers for stopping the scraper device 100 at each of the standby position and the rotation end position.

[0100] The standby position side stopper 135 has a boss portion 137 having a female thread portion and a stopper bolt 138 screwed into the boss portion 137. The boss portion 137 is fixed to the lower left side of the rear bent surface portion 105e by welding or the like, with the axial direction of the stopper bolt 138 being perpendicular to the plate surface of the base plate 105. The stopper bolt 138 protrudes upward from the base plate 105, and forms a flat stopper surface 138a with its head. The stopper surface 138a has a substantially elliptical shape with the longitudinal direction being the front-rear direction, and is a surface parallel to the plate surface of the base plate 105. A nut portion 138b for fastening is provided at the middle portion of the stopper bolt 138 (see FIG. 7).

[0101] On the other hand, a first abutment pin 139 is provided on the scraper support portion 110 side as a portion that abuts against the standby position side stopper 135. The first abutment pin 139 is an elastic member made of an elastic material such as rubber, and is fixed to the support protrusion portion 112b of the lower bracket 112 while passing through the support protrusion portion 112b. The first abutment pin 139 has an abutment surface 139a below the support protrusion portion 112b, which serves as a mating surface with the stopper surface 138a. The abutment surface 139a is a flat circular surface that is parallel to the stopper surface 138a of the scraper device 100 in the standby state.

[0102] When the stopper surface 138a of the standby position stopper 135 comes into contact with the abutment surface 139a of the first abutment pin 139, the scraper device 100 is restricted from rotating in the right direction (clockwise direction) as viewed from the rear from the standby position.

[0103] The rotation end position stopper 136 is provided on the scraper support portion 110 side and has the same configuration as the standby position side stopper 135. The rotation end position stopper 136 has a boss portion 142 and a stopper bolt 143. The boss portion 142 is fixed to the rear side of the rear wall surface portion of the upper and lower intermediate portion of the lower bracket 112 by welding or the like, with the axial direction of the stopper bolt 143 being perpendicular to the lower bracket 112 extending vertically in rear view, that is, in the left-right direction. The stopper bolt 143 protrudes to the right side from the lower bracket 112 and forms a stopper surface 143a. The stopper surface 143a has a substantially elliptical shape with the vertical direction as the longitudinal direction, and is a vertical surface. A nut portion 143b is provided at the middle portion of the stopper bolt 143 (see FIG. 7).

[0104] On the other hand, the scraper device 100 is provided with a second abutment pin 144 as a portion that abuts against the rotation end position stopper 136. The second abutment pin 144 is a member similar to the first abutment pin 139, and is fixed to the pin support portion 105f formed on the base plate 105 on the side opposite the arm support portion 105b side while passing through the pin support portion 105f. The second abutment pin 144 has an abutment surface 144a on the upper side of the pin support portion 105f, which serves as a mating surface with the stopper surface 143a. The abutment surface 144a is a flat circular surface that is parallel to the stopper surface 143a when the scraper device 100 is at the rotation end position.

[0105] When the abutment surface 144a of the second abutment pin 144 contacts the stopper surface 143a of the rotation end position stopper 136, the scraper device 100 is restricted from rotating left (counterclockwise) from the rotation end position as viewed from the rear.

[0106] Regarding the rotational movement of the scraper device 100, a holding bar 151 and a bar gripper 152 are provided for temporarily holding the scraper device 100 in the standby position against the scraper support part 110. The holding bar 151 is a straight bar-shaped member, and extends upward from the upper plate surface of the base plate 105 in a direction perpendicular to the plate surface of the base plate 105. The holding bar 151 is provided in a portion of the base plate 105 between the portion where the opening 105a is formed and the arm support part 105b.

[0107] Rod gripping portion 152 is an elastic member made of an elastic material such as rubber, has a generally rectangular plate-like outer shape, and has front and rear gripping pieces 152a on the lower side for gripping the upper end of holding rod 151. Rod gripping portion 152 has a generally "U" shape formed by front and rear gripping pieces 152a, which form a notched recess 152b that receives the upper end of holding rod 151 with the lower side open.

[0108] The rod gripping portion 152 is provided in a state in which it is fixedly supported by a support stay 153 provided on the front side of the lower bracket 112. The support stay 153 is a plate-like portion having a predetermined shape, and is provided on the front side of the front wall portion of the lower bracket 112. The support stay 153 is roughly "L" shaped in a plan view from the lower bracket 112, wraps around the front side of the upper bracket 111, and extends to the left side, and has a tip support portion 153a at its tip that supports the rod gripping portion 152.

[0109] Tip support part 153a is inclined so as to be parallel to the plate surface of base plate 105, and supports rod gripping part 152 on its upper side. Rod gripping part 152 is fixed to tip support part 153a at two points, one at the front and one at the back, by pins 154 that penetrate tip support part 153a and the base of rod gripping part 152. Pin 154 is fixed by passing a clip pin through the tip part protruding upward from rod gripping part 152, for example.

[0110] The rod gripping portion 152 has a pair of gripping pieces 152a protruding downward from the tip support portion 153a, and temporarily holds the upper end of the holding rod 151, which rotates as part of the scraper device 100 returning to the standby position, in a manner that the pair of gripping pieces 152a grips it. That is, the tip of the holding rod 151, which rotates with the force of the scraper device 100 returning to the standby position, pushes open the recess 152b with elastic deformation of the rod gripping portion 152, and the tip of the holding rod 151 is caught by the rod gripping portion 152, and the standby state of the scraper device 100 is maintained.

[0111] The driving cam 101 will be described. The driving cam 101 acts on the scraper device 100 in conjunction with the upward movement of the hole opener 40, thereby operating the scraper device 100 to cause the three scrapers 102 to act on the hole opener 40.

[0112] The driving cam 101 is provided so as to rotate integrally with the rotary case 42 which rotates about the fulcrum shaft 46. The driving cam 101 is provided with respect to the rotary case 42 via a guide support plate 160.

[0113] The guide support plate 160 is a plate-like member having a predetermined shape with the plate thickness direction of most of it being in the left-right direction, and is provided in a state where it is fixed to the rotary case 42, and rotates integrally with the rotary case 42. The guide support plate 160 has a longitudinal base 161 along one long side of the rotary case 42, and a curved base 162 along one curved portion in the longitudinal direction of the rotary case 42, and these bases form a fixed base that is approximately "L"-shaped or approximately "J"-shaped.

[0114] The guide support plate 160 has its fixed base positioned on the right side of the rotary case 42, and is fastened to the rotary case 42 at three locations by bolts 164 and nuts 165. The bolts 164 pass through bosses formed on the outer periphery of the rotary case 42 and the guide support plate 160, and are screwed into the nuts 165 on the right side of the guide support plate 160. The fixing portions using the bolts 164 are provided at three locations: one end of each of the elongated base portion 161 and the curved base portion 162, and a corner formed by these bases (see FIG. 8).

[0115] The guide support plate 160 has a portion that protrudes from the rotary case 42 on the opposite side to the output shaft 59 side in the longitudinal direction of the rotary case 42, and this protruding portion serves as a cam support portion 166 that supports the drive cam 101. The cam support portion 166 is a portion that protrudes outward from the driven sprocket 52 fixed to the rotary case 42.

[0116] The driving cam 101 is a bent plate-like member obtained by bending a substantially rectangular plate-like member into a substantially crank shape. The driving cam 101 has, as its substantially crank-shaped bent portions, a support plate portion 171 which serves as a support portion for the cam support portion 166, an intermediate plate portion 172 which is bent at a right angle from the outside of the support plate portion 171, and an action plate portion 173 which is bent at a right angle from the outside of the intermediate plate portion 172 and serves as an action portion for the driven roller 108 (see FIGS. 10 and 11).

[0117] The drive cam 101 is supported by the cam support portion 166 with a support plate portion 171 aligned along the right side of the cam support portion 166 by a cam support shaft 174 whose axial direction is in the left-right direction. The cam support shaft 174 passes through the cam support portion 166 and the support plate portion 171, and is inserted into a cylindrical boss portion 167 protruding from the left side of the cam support portion 166.

[0118] The driving cam 101 has a support plate portion 171 located on the right side of the cam support portion 166, an intermediate plate portion 172 extending to the left side of the cam support portion 166 via the outside of the cam support portion 166, and an action plate portion 173 positioned on the left side of the cam support portion 166. In other words, the driving cam 101 has the action plate portion 173 positioned on the left side of the cam support portion 166 in the left-right direction and protruding from the cam support portion 166, forming a protruding piece portion protruding outward (rearward) from the cam support portion 166.

[0119] The driving cam 101 acts on the scraper device 100 by bringing the action plate portion 173 into contact with the driven roller 108 of the scraper device 100. For this reason, the driving cam 101 is provided such that the rotational trajectory of the action plate portion 173 interferes with the driven roller 108 of the scraper device 100 in the standby position with respect to the rotational movement integral with the rotary case 42 about the fulcrum shaft 46.

[0120] When the rotary case 42 rotates clockwise as viewed from the left side, the driving cam 101 brings the action plate portion 173 into contact with the driven roller 108 of the scraper device 100 in a standby state from above. In detail, the action plate portion 173 is inclined at an angle of about 40 to 50° with respect to the left-right direction as viewed in the axial direction of the rotation shaft C1, and contacts the driven roller 108 with the action surface 173a, which is the plate surface on the contact side with the driven roller 108, facing the lower right side.

[0121] The driving cam 101 collides with the driven roller 108 by striking the driven roller 108 with the action plate portion 173, accompanied by the momentum of rotation of the rotary case 42. The scraper device 100 in the standby position rotates about the rotation axis C1 by receiving the collision action of the driving cam 101 on the driven roller 108, and causes the scraper 102 to act on the hole opening device 40. Here, the collision action of the driving cam 101 against the driven roller 108 causes the rod gripping portion 152 to elastically deform, and the holding of the retaining rod 151 by the rod gripping portion 152 is released.

[0122] The driving cam 101 is provided so as to be retractable relative to the cam support portion 166 of the guide support plate 160 so as to be in a stored state in a position (hereinafter referred to as the "storage position") where the rotational trajectory of the acting plate portion 173 does not interfere with the driven roller 108. In other words, the driving cam 101 is provided so as to be positionally changeable relative to the guide support plate 160 so as to be switchable between an operating state in which the driving cam 101 acts on the driven roller 108 to operate the scraper device 100 (hereinafter referred to as the "operating position") and a stored state in which the driving cam 101 does not act on the driven roller 108.

[0123] The mechanism for changing the position of the drive cam 101 will be described with reference to Fig. 11. Fig. 11 is a right side view of the drive cam 101 and its support structure, in which the housed state of the drive cam 101 is indicated by a solid line, and the operating state is indicated by a two-dot chain line.

[0124] 11, the drive cam 101 is supported by the cam support portion 166 so as to be rotatable about a shaft support portion formed by a cam support shaft 174. A cam support spring 180 is provided between the drive cam 101 and the cam support portion 166 for holding the drive cam 101 relative to the cam support portion 166 at each of the operating position and the stored position.

[0125] The cam support spring 180 is disposed on the right side of the cam support portion 166. The cam support spring 180 is a coil spring having locking portions at both ends, with the locking portion at one end locked to a fixed side support pin 181 protruding rightward from the cam support portion 166, and the locking portion at the other end locked to a movable side locking pin 182 fixed to the drive cam 101 in a state protruding rightward from the support plate portion 171 of the drive cam 101. These pins are disposed parallel to each other with their axial direction being the left-right direction.

[0126] In a configuration in which the rotary case 42 and the guide support plate 160 rotate integrally around the fulcrum shaft 46, the fixed side support pin 181 is disposed on the opposite side of the line connecting the axial center position of the fulcrum shaft 46 and the axial center position of the cam support shaft 174 with the rotation of the guide support plate 160 (the lower side in the state shown in FIGS. 6 and 11) in a left side view shown in FIG. 6, for example, and the movable side locking pin 182 is disposed on the opposite side of the line connecting the axial center position of the fulcrum shaft 46 and the axial center position of the cam support shaft 174 with the movement direction side of the cam support shaft 174 accompanying the rotation of the guide support plate 160 (the lower side in the state shown in FIGS. 6 and 11). In other words, the fixed side support pin 181 is disposed on the opposite side of the cam support shaft 174 in the rotation direction of the guide support plate 160 (the counterclockwise direction in the right side view shown in FIG. 11), and the movable side locking pin 182 is disposed on the rotation direction side of the cam support shaft 174. The movable-side locking pin 182 penetrates the support plate portion 171 of the drive cam 101 and also penetrates the cam support portion 166 through a guide hole 166a formed in the cam support portion 166, with its tip end protruding to the left of the cam support portion 166. The guide hole 166a has a curved shape that follows an arc centered on the axis of the cam support shaft 174. The cam support spring 180 is a tension spring, and urges the movable-side locking pin 182 in a direction approaching the fixed-side support pin 181 by its elastic force.

[0127] In the above-described configuration, the cam support spring 180 is located on one side of the cam support shaft 174 (upper left side in FIG. 11) with respect to the drive cam 101 in the operating position, and holds the drive cam 101 in the operating position by its biasing force. The drive cam 101 in the operating position moves to the stored position by rotating about 90° in the rotation direction of the rotary case 42 (counterclockwise direction when viewed from the right side) about the cam support shaft 174 (see arrow E1 in FIG. 11). Here, the movable side locking pin 182 moves along the guide hole 166a together with the drive cam 101.

[0128] When the drive cam 101 moves from the operating position to the storage position, the movable locking pin 182 is positioned on the opposite side of the cam support shaft 174 to the position of the drive cam 101 in the operating state. The cam support spring 180 is positioned on the other side of the cam support shaft 174 (the lower right side in FIG. 11) with respect to the drive cam 101 in the storage state, and holds the drive cam 101 in the storage position by the biasing force. The drive cam 101 in the storage position is locked to the cam support portion 166 by contacting the corner portion of the support plate portion 171 and the intermediate plate portion 172 with the step portion 166b formed in the cam support portion 166, and is restricted in the rotation in the rotation direction from the operating position to the storage position by the action of the cam support spring 180. The drive cam 101 in the storage position moves to the operating position by rotating about 90° around the cam support shaft 174 opposite to the rotation direction of the rotary case 42 (clockwise direction when viewed from the right side) (see arrow E2 in FIG. 11).

[0129] In the rotational movement of the drive cam 101, the movable locking pin 182 moves within an angular range of about 30° around the fixed support pin 181. The guide hole 166a is formed in a circumferential direction around the fixed support pin 181 over an angular range (for example, about 40°) including the movement range of the movable locking pin 182 accompanying the switching of the state of the drive cam 101. As shown in FIG. 11, in a side view, the positions of the cam support spring 180 and the movable locking pin 182 in both the operating state and the stored state of the drive cam 101 are line-symmetrical or approximately line-symmetrical with respect to a straight line L1 passing through the center of the fixed support pin 181 and the center of the cam support shaft 174. In this way, the drive cam 101 is supported by the cam support portion 166 in a state where it is biased by the cam support spring 180, and rotates in a manner of crossing a fulcrum that moves the movable locking pin 182 beyond the straight line L1 when switching between the operating state and the stored state.

[0130] Further, in the support structure for the drive cam 101, a cam adjustment mechanism 185 for adjusting the position of the drive cam 101 in the operating state is provided. The cam adjustment mechanism 185 has a boss portion 186 having a female thread portion, and an adjustment bolt 187 screwed into the boss portion 186. The cam adjustment mechanism 185 is provided in a state in which the boss portion 186 is fixed to the plate surface on the left side of the cam support portion 166 by welding or the like.

[0131] The boss portion 186 has an adjustment bolt 187 screwed therethrough, and the tip portion of the adjustment bolt 187 is provided to abut against the movable-side locking pin 182 of the drive cam 101 in the actuated state from the side opposite the storage position. The drive cam 101 in the actuated position is locked by abutting the tip portion of the movable-side locking pin 182 against the tip portion 187a of the adjustment bolt 187, and is restricted in its rotation in the rotation direction from the storage position to the actuated position by the action of the cam support spring 180. A fastening nut portion 188 is provided at the middle portion of the adjustment bolt 187 (see FIG. 11).

[0132] In this configuration, the angle of the drive cam 101 at the operating position, that is, the rotation position at which the movable locking pin 182 abuts against the adjustment bolt 187, is adjusted with respect to the rotation position of the drive cam 101 about the cam support shaft 174, by adjusting the amount of screwing of the adjustment bolt 187 into the boss portion 186. By changing the angle of the drive cam 101 at the operating position, the position of the action plate portion 173 protruding outward from the cam support portion 166 changes, and the timing at which the action plate portion 173 abuts against the driven roller 108 changes during the rotation of the drive cam 101 accompanying the rotation of the rotary case 42. According to the cam adjustment mechanism 185, the timing at which the scraper device 100 abuts against the hole opener 40 can be adjusted by adjusting the position of the adjustment bolt 187 during the periodic lifting and lowering of the hole opener 40.

[0133] The guide support plate 160, which supports the drive cam 101 relative to the rotary case 42, has a guide plate portion 168 that restricts movement of the driven roller 108 within a predetermined angle range during rotational movement of the rotary case 42 around the fulcrum shaft 46 to hold the scraper device 100 in a standby position. When viewed in the axial direction of the fulcrum shaft 46 (side view), the guide plate portion 168 has a shape that follows a circumference centered on the fulcrum shaft 46 so as to overlap with the driven roller 108 of the scraper device 100 in a standby state located at a predetermined distance from the fulcrum shaft 46 within a predetermined angle range during rotational movement of the guide support plate 160 around the fulcrum shaft 46.

[0134] The guide plate portion 168 has an arc-like curved shape having a substantially constant width when viewed in the axial direction of the fulcrum shaft 46. In this embodiment, the guide plate portion 168 is provided to cover an angle range of approximately 150 to 160° with respect to a circumference centered on the fulcrum shaft 46, and has a substantially semicircular shape. The guide plate portion 168 is connected to the longitudinal base portion 161 of the guide support plate 160 via a substantially "T"-shaped support frame portion 169 that is installed on the inner periphery side of the semicircular shape of the guide plate portion 168.

[0135] The edge of the longitudinal base 161 is bent leftward, and the guide plate 168 and the support frame 169 are located on the left side of the longitudinal base 161, etc., which are located on the right side of the rotary case 42, and are located within the range of the left-right dimension (case thickness direction) of the rotary case 42. The guide plate 168 is provided so as to be located on the right side of the driven roller 108 of the scraper device 100 in the standby state.

[0136] The guide plate portion 168 is located on the right side of the driven roller 108 within an angular range of approximately half of one revolution in the rotational movement of the rotary case 42 with respect to the scraper device 100 in the standby state, and restricts the movement of the scraper device 100 toward the rotation end position side about the rotation axis C1 by abutting against the driven roller 108. Both ends of the guide plate portion 168 are bent portions 168a that are slightly bent to the right. The bent portions 168a function as guide portions for positioning the guide plate portion 168 to the right side of the driven roller 108 without colliding with the driven roller 108 as the rotary case 42 rotates.

[0137] The operation of the hole opening device 40 and the scraper device 100 having the above-mentioned configuration will be described with reference to Figures 12 to 16. In each of Figures 12 to 16, Figure A is a left side view, and Figure B is a rear view.

[0138] 12A and 12B show the state where the hole opening device 40, which moves up and down in conjunction with the rotation of the rotary case 42 around the fulcrum shaft 46, is at the lower end position. At the lower end position, the hole opening device 40 opens a pair of planting claws 45 in a vertical posture to plant seedlings in the furrows. In the open hole opening device 40, an inter-claw space portion S1, which is an open space portion, exists between the mating surfaces 45a of the front and rear planting claws 45, which are gradually widened from the top to the bottom (see FIG. 12A). Regarding the rotational movement of the rotary case 42, as shown in FIG. 12A and FIG. 12B, the rotation angle of the rotary case 42 at the timing when the hole opening device 40 is at the lower end (hereinafter referred to as the "case rotation angle") is 0°, and the rotation position of the rotary case 42 at the same timing is the reference position.

[0139] When the case rotation angle is 0°, the scraper device 100 is in a standby state. In this state, the scraper device 100 retracts the three scrapers 102 from the operating range of the hole opener 40 so as not to interfere with the operating range of the hole opener 40 that moves up and down. In addition, when the scraper device 100 is in a standby state, the holding rod 151 is held by the rod gripping portion 152, and the driven roller 108 is restricted from moving rightward by the guide plate portion 168 located to the right of the holding rod 151.

[0140] 13A and 13B show a state where the case rotation angle is 60°. In this state, the hole opening device 40 is raised from the lower end position while maintaining the pair of planting claws 45 in an open state as the rotary case 42 rotates and taking a forward tilting posture due to the guiding action of the lift guide 43 and the operation of the arm 44.

[0141] When the case rotation angle is 60°, the scraper device 100 is in a standby state. In this state, the guide plate portion 168 has a bent portion 168a at the end side in the rotation direction of the rotary case 42 positioned to the right of the driven roller 108.

[0142] 14A and 14B show a state where the case rotation angle is 75°. In this state, the hole opening device 40 is slightly raised from the state where the case rotation angle is 60° while keeping the pair of planting claws 45 open and tilted forward.

[0143] The state where the case rotation angle is 75° is the state immediately after the driving cam 101 collides with the driven roller 108. In other words, this state is the state immediately after the scraper device 100 starts to rotate from the standby position to the rotation end position. Therefore, the driving cam 101 collides with the driven roller 108 from above at a predetermined timing when the case rotation angle becomes from 60° to 75°.

[0144] When the driving cam 101 collides with the driven roller 108, the impact causes the scraper device 100 to start rotating about the rotation axis C1 in a direction that brings the scraper 102 closer to the hole opening device 40, that is, in the counterclockwise direction when viewed from the rear (see arrow F1). Just before the scraper device 100 starts rotating, the guide plate portion 168 moves away from the driven roller 108 in the rotation direction about the fulcrum axis 46, so that the guide action of the guide plate portion 168 on the driven roller 108 is interrupted and the restriction on the rightward movement of the driven roller 108 is released.

[0145] As the scraper device 100 starts to rotate, the holding rod 151 comes off the rod gripping portion 152. The scraper device 100 also rotates from the standby state against the biasing force of the return spring 128. As the scraper device 100 starts to rotate from the standby position around the rotation axis C1, the three scrapers 102 start to approach the hole opening device 40.

[0146] 15A and 15B show a state where the case rotation angle is 90°. In this state, the hole opening device 40 is slightly raised from the state where the case rotation angle is 75° while maintaining the pair of planting claws 45 in an open state and in a forward tilted state.

[0147] The state where the case rotation angle is 90° is the state when the scraper device 100 reaches the rotation end position. The scraper device 100 stops at the rotation end position by abutting the second abutment pin 144 against the rotation end position stopper 136. When the scraper device 100 is in the rotation end state, the driving cam 101 acting on the driven roller 108 from above is located directly below the driven roller 108.

[0148] By moving the movable-side support pin 132, which engages one end of the return spring 128, the scraper device 100 rotates over a fulcrum about the scraper support shaft 115 located between the fixed-side support pin 131 and the movable-side support pin 132 before going from the standby state to the rotation end state. In other words, the scraper device 100 moves the movable-side support pin 132 relative to the fixed-side support pin 131 so that the return spring 128, which was located below the scraper support shaft 115 in the standby state, is located above the scraper support shaft 115 in the rotation end state.

[0149] In the rotation end state of the scraper device 100, all three scrapers 102 are located on the right side of the hole opener 40. In other words, the scraper device 100 causes the three scrapers 102 to pass from the left side to the right side of the hole opener 40 in an open state with the pair of planting claws 45 open before reaching the rotation end position, so that the three scrapers 102 act simultaneously on the hole opener 40.

[0150] When the scraper device 100 is at the end of its rotation, the three scrapers 102 located on the right side of the hole opener 40 are all oriented with their plate surfaces aligned vertically and their plate thicknesses aligned left-right. In other words, the three scrapers 102 gradually rise from a left-downward inclination in the standby state as they approach the hole opener 40, and act on the hole opener 40 in the process of becoming vertical.

[0151] The inner scraper 102A, located in the front-rear center, passes through the inter-tine space S1 between the front and rear planting tines 45 when the hole opening device 40 is in the open state, thereby cleaning the inside of each planting tine 45. In detail, the inner scraper 102A cleans the inside of the front and rear planting tines 45 by acting on the inside of the front and rear planting tines 45 while elastically deforming the fin-shaped portions on both the front and rear sides.

[0152] The front scraper 102B cleans the outside of the front planting claw 45 with respect to the open hole opening device 40. In detail, the front scraper 102B cleans the outside of the front planting claw 45 by acting on the outer surface of the front planting claw 45 while elastically deforming the fin-shaped portion facing the rear side, in a manner of sweeping the outside of the front planting claw 45.

[0153] The rear scraper 102C cleans the outside of the rear planting claw 45 with respect to the open hole opening device 40. In detail, the rear scraper 102C cleans the outside of the rear planting claw 45 by applying elastic deformation to the outer surface of the rear planting claw 45 while elastically deforming the fin-shaped portion facing the front side.

[0154] 16A and 16B show a state where the case rotation angle is 105°. In this state, the hole opening device 40 is raised from a state where the case rotation angle is 90° while maintaining the pair of planting claws 45 in an open state and tilting forward.

[0155] The state where the case rotation angle is 105° is the state when the scraper device 100 returns from the rotation end position to the standby position. The scraper device 100 stops at the standby position by abutting the standby position side stopper 135 against the first abutment pin 139. In the process where the scraper device 100 returns from the rotation end position to the standby position, the three scrapers 102 pass below the raised hole opening device 40.

[0156] Thereafter, as the rotary case 42 continues to rotate, the hole opener 40 rises, closes the pair of planting claws 45 near the rising end to enter a closed state, and receives seedlings from the seedling supply unit 4 at the rising end position. The hole opener 40 that has received the seedlings descends in the closed state, opens at the falling end position, i.e., when the case rotation angle is 0°, and plants the seedlings. From the state where the case rotation angle is 0° (see Figs. 12A and 12B), the scraper device 100 cleans the hole opener 40 as described above. In the process of the hole opener 40 descending from the rising end, at a predetermined timing when the case rotation angle becomes about 260 to 270°, the tip of the guide plate portion 168 reaches the driven roller 108, and the guide plate portion 168 restricts the movement of the driven roller 108 to the right.

[0157] The seedling transplanter 1 equipped with the hole opener 40 and scraper device 100 that perform the above-mentioned operations has the following configuration. That is, the drive cam 101 moves the three scrapers 102 from the retracted position to the cleaning position where they act on the hole opener 40, in accordance with the upward movement of the hole opener 40.

[0158] The retracted position for the scraper 102 is the position of the scraper 102 in the scraper device 100 in a standby state, and is a position retracted from the operating range of the hole opener 40. The cleaning position for the scraper 102 is the position in a state in which the scraper 102 is performing a cleaning action on the hole opener 40, and is a position within a predetermined moving range immediately before the scraper device 100 reaches the rotation end state.

[0159] The seedling transplanter 1 is equipped with a traveling machine body 2 on which the seedling planting device 3 is mounted, and the hole opener 40 is provided to move up and down relative to the traveling machine body 2. The scraper device 100 is configured to move the scraper 102 into and out of the hole opener 40 from one side in a direction perpendicular to the opening and closing direction of the hole opener 40 in a plan view.

[0160] The opening and closing direction of the hole opening device 40, which opens and closes the pair of front and rear planting claws 45, is the front-rear direction in a plan view. The scraper device 100 rotates around the rotation axis C1 to cause the three scrapers 102 to enter and retreat from the left side, which is one side in the left-right direction perpendicular to the front-rear direction in a plan view, with respect to such a hole opening device 40. That is, the scraper device 100 rotates around the rotation axis C1 along the front-rear direction in a plan view, and cleans the hole opening device 40 by making the three scrapers 102 located below the rotation axis C1 cross the hole opening device 40 from the left side to the right side at the front, inner, and rear positions of the hole opening device 40 in the open state. Then, the three scrapers 102 that have cleaned the hole opening device 40 move to the left side from the hole opening device 40 and retreat by the rotation of the scraper device 100 returning to the standby position.

[0161] According to the seedling transplanter 1 of this embodiment having the above-mentioned configuration, the scraper device 100 for removing soil and the like adhering to the hole opener 40 has a relatively simple configuration and can obtain good tracking ability with the hole opener 40 as it rises and falls, and can perform accurate operation synchronized with the operation of the hole opener 40.

[0162] As the hole opener 40 ascends, the scraper device 100 rotates by receiving the impact of the driving cam 101, which rotates integrally with the rotary case 42, at the driven roller 108, and operates to push the three scrapers 102 into the open hole opener 40. With such a simple configuration, the rotational movement of the scraper device 100 can be easily synchronized with the ascending and descending movement of the hole opener 40, and the scraper device 100 can be operated with accurate timing. Furthermore, good follow-up to the ascending and descending movement of the hole opener 40 can be obtained, so the scraper device 100 can be operated accurately even with respect to the hole opener 40 that operates at high speed.

[0163] In addition, the driving cam 101 is provided so as to act on the scraper device 100 with the upward movement of the hole opener 40, and move the scraper 102 from the retreated position to the cleaning position. With this configuration, the scraper device 100 is located at the standby position during the downward movement of the hole opener 40 holding the seedlings 9 received by the hole opener 40 from the seedling supply unit 4, so that the scraper device 100 can be prevented from interfering with the hole opener 40. In addition, since the scraper 102 moves to the cleaning position during the upward movement of the hole opener 40, a sweeping action is obtained downward by the relative downward movement of the scraper 102 with respect to the ascending hole opener 40, and it becomes possible to efficiently remove soil and the like adhering to the hole opener 40.

[0164] Moreover, the scraper device 100 is configured so that the scraper 102 enters and leaves the hole opening device 40, which opens and closes in the front-rear direction, from the side. With this configuration, it is easy to prevent the scraper device 100 from interfering with the hole opening device 40. Also, since a predetermined range of movement in the stroke of the scraper device 100 entering and leaving the hole opening device 40 is the range of action on the hole opening device 40, the range of action of the scraper 102 on the hole opening device 40 can be expanded, and the hole opening device 40 can be cleaned efficiently. Also, since there is no need to secure space for arranging the scraper 102 and the like in front of and behind the hole opening device 40, a compact device configuration can be realized as the arrangement configuration of the scraper device 100.

[0165] The scraper device 100 also has a driven roller 108 as a part that is acted upon by the driving cam 101 provided on the rotary case 42. With this configuration, the scraper device 100 can be operated by causing the driving cam 101 to act on the driven roller 108 in accordance with the rotation of the rotary case 42 synchronized with the lifting and lowering operation of the hole opener 40, so that the scraper device 100 can be operated in accurate synchronization with the operation of the hole opener 40 with a simple configuration.

[0166] The scraper device 100 has, as the scrapers 102, an inner scraper 102A which is an inner cleaning body, and a front scraper 102B and a rear scraper 102C which are outer cleaning bodies. With this configuration, soil and the like can be removed simultaneously from both the inside and outside of the hole opening device 40. Furthermore, with a configuration in which the three scrapers 102 are supported on a common base plate 105 via a scraper arm 107, it is possible to simplify the structure without providing an operating mechanism for each scraper 102, and further, it is possible to simultaneously clean the inside and outside of the hole opening device 40 by a single action of rotating the scraper device 100. This allows efficient cleaning within the limited time within the stroke of the lifting and lowering movement of the hole opening device 40.

[0167] Moreover, the scraper device 100 has a return spring 128 for returning to the standby position after acting on the hole opener 40. With such a configuration, the scraper device 100 can be held in the standby position, so that it is possible to prevent the scraper device 100 from unnecessarily interfering with the hole opener 40, for example, while the hole opener 40 is descending.

[0168] In addition, in the configuration provided with the return spring 128, the scraper device 100 is configured to cross the fulcrum of the scraper support shaft 115 during rotation between the standby position and the rotation end position. With this configuration, the action of the scraper 102 acting on the hole opening device 40 can be assisted by the biasing force of the return spring 128, so that the scraper 102 can be reliably acted on the hole opening device 40. In addition, in the rotational action of the scraper device 100 returning from the rotation end position to the standby position, the action (biasing force) in the return direction by the return spring 128 decreases near where the return spring 128 crosses the fulcrum, so the configuration of crossing the fulcrum does not hinder the removal of soil and the like attached to the hole opening device 40 by the scraper 102. Here, although the return action of the return spring 128 decreases near the fulcrum, the scraper device 100 can achieve good operability in the rotational movement in the direction returning to the standby position due to the action of its own weight.

[0169] In addition, a holding rod 151 and a rod gripper 152 are provided as a structure for holding the scraper device 100 in the standby position. With this structure, the scraper device 100 that has returned from the rotation end position to the standby position can be temporarily fixed in the standby position until it is next acted upon by the drive cam 101, so that flapping of the scraper device 100 due to vibration of the machine body or bouncing of the scraper device 100 can be suppressed. This makes it possible to prevent the scraper device 100 from interfering with the hole opening device 40.

[0170] Furthermore, the guide support plate 160 that supports the drive cam 101 on the rotary case 42 has a guide plate portion 168 that guides and holds the driven roller 108 to a position in the standby state of the scraper device 100. With this configuration, the scraper device 100 can be held in the standby position via the driven roller 108, so flapping of the scraper device 100 due to vibration of the machine body or bouncing of the scraper device 100 can be suppressed. This makes it possible to prevent the scraper device 100 from interfering with the hole opening device 40.

[0171] Moreover, the three scrapers 102 are arranged to trace a trajectory that enters the hole opening device 40 in the open state from the diagonally lower left side when viewed from behind, and penetrates and exits to the right side. With this configuration, the scrapers 102 can easily deform along the shape of the hole opening device 40, and the scrapers 102 can reliably clean the hole opening device 40 from the entry side (left side) to the end on the opposite side (right side). Also, by the scrapers 102 passing through the hole opening device 40 from left to right, soil and the like adhering to the hole opening device 40 can be discharged toward the outside (right side) of the hole opening device 40.

[0172] Further, the driving cam 101 is provided so that its position can be adjusted by the cam support spring 180 and the cam adjustment mechanism 185. With such a configuration, it is possible to adjust the phase at which the driving cam 101 acts on the driven roller 108 in accordance with the lifting and lowering operation of the hole opening device 40 so that the cleaning effect of the scraper device 100 is maximized, thereby obtaining good cleaning performance.

[0173] Moreover, the driving cam 101 is provided so as to be retractable so as to be in a non-acting state with respect to the driven roller 108. With this configuration, when cleaning by the scraper device 100 is not required, the driving cam 101 can be retracted to prevent unnecessary wear of the driving cam 101 and the driven roller 108, which come into contact with each other, the scraper 102 acting on the hole opening device 40, and the like.

[0174] [Other embodiments of the scraper device and its operating mechanism] A configuration example of a scraper device 200 according to another embodiment will be described with reference to Fig. 17 to Fig. 22. In this embodiment, the same names or the same reference numerals will be used for configurations common to or corresponding to the above-described embodiment, and descriptions of overlapping contents will be omitted as appropriate.

[0175] This embodiment differs from the above-described embodiment mainly in that a drive cam 201 for operating the scraper device 200 is provided on the hole opener 40 side. The drive cam 201 is an operating member for operating the scraper device 200, and acts on the scraper device 200 in conjunction with the lifting and lowering operation of the hole opener 40. The scraper device 200 has a scraper 202 as a cleaning body that acts on the hole opener 40, and removes soil and the like adhering to the hole opener 40 by scraping it off with the scraper 202.

[0176] 17 to 19 and 22 show the scraper device 200 in a standby state, and Fig. 20 and Fig. 21 show the rotation end state of the scraper device 200. In the description of the scraper device 200, the standby state is used as a reference.

[0177] The scraper device 200 has, as scrapers 202, an inner scraper 202A acting on the inside of a pair of planting claws 45, a front scraper 202B acting on the outside of the front planting claw 45, and a rear scraper 202C acting on the outside of the rear planting claw 45. Of these three scrapers 202, the inner scraper 202A is an example of an inner cleaning body acting on the inside of the hole opening device 40, and the front scraper 202B and the rear scraper 202C are examples of outer cleaning bodies acting on the outside of the hole opening device 40.

[0178] The scraper device 200 has a base plate 205, a scraper arm 207 fixed to the base plate 205 and supporting each scraper 202, a driven roller 208 fixed to the base plate 205, and a support part 109 that supports the base plate 205. As in the above-described embodiment, the scraper device 200 is supported by the rear end part of the left rear frame 31 via a scraper support part 110, and is rotatable within a predetermined angle range around a rotation axis C1 relative to the scraper support part 110.

[0179] The base plate 205 is a flat plate having a predetermined shape, and the plate surface is inclined downward toward the front along the axial direction of the rotation axis C1 in a side view, and is inclined downward from the left-right inner side (right side) to the left-right outer side (left side) in a rear view. The base plate 205 is located on the lower right side of the pivot support 109, and is fixed to the outer circumferential cylinder portion 109a of the pivot support 109 by welding or the like.

[0180] As in the above-described embodiment, the base plate 205 has the pivot support 109 fixed to its rear portion at a portion where a rectangular opening 205a is formed. The base plate 205 is supported on the scraper support shaft 115 so as to be rotatable integrally with the outer circumferential cylinder portion 109a of the pivot support 109 around the axis of the scraper support shaft 115 (around the pivot axis C1).

[0181] The base plate 205 has an arm support part 205b on the front left side of the fixed part of the shaft support part 109, which supports multiple (three) scraper arms 207. Scraper arms 207 supporting each of the scrapers 202, the front scraper 202B, the inner scraper 202A, and the rear scraper 202C, are attached to the arm support part 205b in this order from the front side to the rear side. A scraper 202 is attached to the tip of each scraper arm 207.

[0182] Each scraper arm 207 is made of a narrow plate-like member having a predetermined bent shape, and is fixed to the base plate 205 at two points by bolts 217 with the base end overlapping the lower side of the arm support part 205b. The bolts 217 pass through the base plate 205 and the base end of the scraper arm 207, and are screwed into a nut part 218 provided on the back side of the scraper arm 207.

[0183] The two fixing parts of each scraper arm 207 by the bolt 217 are provided at an interval in the longitudinal direction of the base end of the scraper arm 207. The hole part through which the lower bolt 217 passes in the arm support part 205b is an elongated hole 205c along a circular arc concentric with the circular hole part through which the upper bolt 217 passes. With this configuration, the scraper arm 207 can rotate back and forth with respect to the base plate 205 within the range of the length of the elongated hole 205c around the fixing part by the upper bolt 217, and the fixing angle of the scraper arm 207 with respect to the base plate 205 can be adjusted. By adjusting the fixing angle of the scraper arm 107, the front-rear position of the scraper 202 can be adjusted.

[0184] The three scraper arms 207 extend downward from the arm support portion 205b of the base plate 205 and support the scraper 202 at positions where they do not interfere with each other. The scraper 202 is a plate-like member made of an elastic material such as rubber, sponge, or plastic.

[0185] When viewed in the axial direction of the rotation shaft C1, the front scraper 202B and the rear scraper 202C are provided at positions where they overlap each other, and the inner scraper 202A is located one step below these scrapers 202. Each scraper 202 is fixed to a scraper attachment part 207a formed at the tip of each scraper arm 207 as a surface part parallel to the scraper 202 and bent relative to the main body of the scraper arm 207.

[0186] The front scraper 202B and the rear scraper 202C are provided symmetrically or approximately symmetrically with respect to a plane perpendicular to the axial direction of the rotation shaft C1. The front scraper 202B and the rear scraper 202C overlap the scraper attachment portion 207a from above, and are sandwiched between the scraper attachment portion 207a and a pressing plate 219 located above each scraper 202.

[0187] The pressing plate 219 is a longitudinal plate-like member, and is provided so that its longitudinal direction is aligned with the longitudinal direction of the scraper mounting portion 207a. The scraper 202 and pressing plate 219 are fastened and fixed to the scraper mounting portion 207a at two locations by two bolts 221 that penetrate both longitudinal ends of the pressing plate 219. The bolts 221 penetrate the pressing plate 219, the scraper 202, and the scraper mounting portion 207a from above, and are screwed into a nut portion 222 provided on the lower side of the scraper mounting portion 207a.

[0188] The front scraper 202B and the rear scraper 202C have a substantially rectangular outer shape, with one edge of the outer shape being the part to be clamped by the scraper attachment part 207a and the pressing plate 219, and most of the other side extending in a fin-like shape from the part to be clamped. The front scraper 202B and the rear scraper 202C have a recess 202d that is an arc-shaped notch part on the edge on the tip side.

[0189] The front scraper 202B and the rear scraper 202C are provided so that their tip sides face each other in the front-rear direction. Therefore, in the front scraper 202B, the front part is fixed by the bolt 221, and the majority of the rear side is a fin-shaped extension. In the rear scraper 202C, the rear part is fixed by the bolt 221, etc., and the majority of the front side is a fin-shaped extension. In these scrapers 202, the fin-shaped extension is the part that mainly elastically deforms by acting on the hole opening device 40. The front scraper 202B and the rear scraper 202C are inclined so that their tip sides are located on the lower side when viewed from the left side, and are inclined downward to the right so that their tip sides are located on the lower right side when viewed from the rear.

[0190] The inner scraper 202A overlaps the scraper mounting portion 207a from the right side, and is supported at one location on the scraper mounting portion 207a by one bolt 223. The bolt 223 passes through the inner scraper 202A and the scraper mounting portion 207a from the right side, and is screwed into a nut portion 224 provided on the left side of the scraper mounting portion 207a.

[0191] The inner scraper 202A has a circular outer shape, and is attached so as to be freely rotatable around the support part, with the center of the outer shape being the support part supported by the bolt 223. In other words, the inner scraper 202A is supported so as to be freely rotatable around the support shaft, the bolt 223 which penetrates through the center of the inner scraper 202A.

[0192] In the inner scraper 202A, the portion outside the support portion for the scraper attachment portion 207a by the bolt 223, i.e., most of the portion excluding the center portion of the circular outer shape, is the portion that is mainly elastically deformed by acting on the hole opening device 40. The inner scraper 202A stands relatively close to vertical, and is inclined downward to the left in rear view, similar to the base plate 205. Therefore, in rear view, the inner scraper 202A, the front scraper 202B, and the rear scraper 202C are provided so as to be inclined in opposite directions to each other in the left-right direction.

[0193] The driven roller 208 is provided at a position to the right rear of the shaft support portion 109, and is rotatably supported by the base plate 205 via a roller support shaft 225. The roller support shaft 225 is a straight rod-shaped member, with its axial direction parallel to the axial direction of the rotation shaft C1 and its axis located to the right of the axis of the rotation shaft C1. When the scraper device 200 is in the standby state, the height position of the axis of the roller support shaft 225 coincides or approximately coincides with the rotation shaft C1.

[0194] The roller support shaft 225 is installed between the rear bent surface portion 205e of the base plate 205 and a support wall portion 205f (see FIG. 22) provided in front of the rear bent surface portion 205e. The rear bent surface portion 205e is a portion formed as a portion bent downward with respect to the main body portion on the rear side of the base plate 205, and the support wall portion 205f is a plate-shaped portion protruding in parallel with the rear bent surface portion 205e on the lower side of the base plate 205. The roller support shaft 225 is configured with a pin member, and is engaged and fixed by penetrating the support wall portion 205f and the rear bent surface portion 205e from the front side and penetrating a clip pin 226 into the rear end portion protruding from the rear bent surface portion 205e.

[0195] The driven roller 208 is a part that receives the action of the driving cam 201, and is a roller that receives the abutment of the driving cam 201 at its outer circumferential surface 208a. The driven roller 208 is composed of a cylindrical bearing member through which the roller support shaft 225 passes. In this embodiment, the driven roller 208 is composed of two bearings of the same diameter that are journaled on the roller support shaft 225 and connected in the axial direction.

[0196] In the above configuration, the scraper device 200 rotates from a standby state leftward (counterclockwise) as viewed from the rear about the rotation axis C1 (see arrow G1 in FIG. 21), causing the three scrapers 202 to act on the hole opening device 40. In the scraper device 200, a rotation unit that rotates integrally with the scraper support shaft 115 about the rotation axis C1 is formed by the base plate 205, the three sets of scraper arms 207 and scrapers 202 and driven rollers 208 attached to the base plate 205, and the outer circumferential cylinder portion 109a of the shaft support portion 109.

[0197] The scraper device 200 is provided so as to be rotatable about the rotation axis C1 within an angle range from a standby position to a rotation end position where the base plate 205 aligns the plate surface in the vertical direction and the three scrapers 202 act on the hole opening device 40 (see FIG. 21). The rotation angle of the scraper device 200 from the standby position to the rotation end position is approximately 45°. However, the magnitude of this rotation angle is not particularly limited.

[0198] With respect to the rotational movement of the scraper device 200, a return spring 128 is provided that acts in a direction returning the scraper device 200 to the standby position, as in the above-described embodiment. The return spring 128 is installed between a fixed-side support pin 131 fixed to the support protrusion 112b of the lower bracket 112 and a movable-side support pin 132 provided on the base plate 205. In this embodiment, the movable-side support pin 132 is fixed by welding or the like to a position near the right side of the pivot support portion 109 at the rear of the base plate 205, and extends rearward from the base plate 205. The return spring 128 is arranged in a slanted manner that is downwardly inclined to the left in the same manner as the inclination of the base plate 205 when viewed from the rear.

[0199] Regarding the rotational movement of the scraper device 200, the scraper device 200 is provided with a standby position side stopper 235 and a rotation end position stopper 236 as stoppers for stopping the scraper device 200 at each of the standby position and the rotation end position.

[0200] The standby position stopper 235 has a boss portion 237 having a female thread portion, and a stopper bolt 238 screwed into the boss portion 237. The boss portion 237 is fixed to the lower left side of the rear bent surface portion 205e by welding or the like, with the axial direction of the stopper bolt 238 oriented perpendicular to the plate surface of the base plate 205. The stopper bolt 238 protrudes upward from the base plate 205, and forms a flat stopper surface 238a with its head portion. A nut portion 238b for fastening is provided at the middle portion of the stopper bolt 238.

[0201] On the other hand, a backing plate 239 is provided on the scraper support portion 110 side as a portion that abuts against the standby position side stopper 235. The backing plate 239 is a rectangular plate-shaped elastic member made of an elastic material such as rubber, and is disposed on the lower surface side of the support protrusion 112b of the lower bracket 112, and is fixed to the support protrusion 112b at two points, front and rear, by bolts 240. The bolts 240 penetrate the backing plate 239 and the support protrusion 112b from the lower side, and are screwed into a nut portion 241 provided on the upper side of the support protrusion 112b. The backing plate 239 has a lower plate surface as a receiving surface 239a that receives the contact of the stopper surface 238a. The receiving surface 239a is a flat surface that is parallel to the stopper surface 238a of the scraper device 200 in the standby state.

[0202] When the stopper surface 238a of the standby position side stopper 235 contacts the receiving surface 239a of the contact plate 239, the scraper device 200 is restricted from rotating in the right direction (clockwise direction) as viewed from the rear from the standby position.

[0203] The rotation end position stopper 236 has a similar configuration to the standby position stopper 235. The rotation end position stopper 236 has a boss portion 242 and a stopper bolt 243. The boss portion 242 is fixed by welding or the like to a position on the upper right side of the rear part of the base plate 205 and above the driven roller 208, with the axial direction of the stopper bolt 243 oriented in a direction parallel to the stopper bolt 238 of the standby position side stopper 235. The stopper bolt 243 protrudes upward from the base plate 205, and forms a flat stopper surface 243a with its head. A nut portion 243b for fastening is provided at the middle of the stopper bolt 243.

[0204] Of the front and rear wall surfaces of the lower bracket 112 constituting the scraper device 100, the front wall surface 112c is the portion that receives the abutment of the rotation end position stopper 236 (see FIG. 22). That is, the scraper device 200 is restricted from rotating left (counterclockwise) as viewed from the rear from the rotation end position by bringing the stopper surface 243a of the stopper bolt 243 into contact with the right end surface 112d of the wall surface 112c.

[0205] The driving cam 201 will now be described. The driving cam 201 is attached to the hole opener 40, and acts on the scraper device 200 as the hole opener 40 ascends, thereby operating the scraper device 200 to cause the three scrapers 202 to act on the hole opener 40.

[0206] As shown in Figures 19 and 23, the drive cam 201 is fixed to the pivot support 68 that pivotally supports the rear planting claws 45 of the hole opening device 40. The rear pivot support 68 has a pair of left and right support plate portions 68a and a rectangular plate-shaped installation plate portion 68b that is installed above the left and right support plate portions 68a.

[0207] The drive cam 201 has a fixed support portion 261 fixed to the shaft support portion 68 with the claw fulcrum shaft 69 passing through the left and right support plate portions 68a, and a cam portion 262 extending to the left side from the fixed support portion 261.

[0208] The fixed support part 261 is a plate-like part that is substantially inverted "U" shape with the lower side open, and has left and right support wall parts 261a with the plate thickness direction being the left-right direction, and an upper surface part 261b connecting the left and right support wall parts 261a. The left and right support wall parts 261a of the fixed support part 261 are respectively overlapped on the left and right outer sides of the left and right support wall parts 72 (see FIG. 23), and the claw fulcrum shaft 69 penetrates through it.

[0209] The fixed support portion 261 has an upper surface portion 261b overlapping the installation plate portion 68b from above, and is fixed to the pivot portion 68 via an attachment plate 263 by welding or the like. As shown in Fig. 23, the attachment plate 263 is a plate-like member bent into a substantially "L" shape, with one surface portion 263a positioned below the installation plate portion 68b and the other surface portion 263b extending upward and positioned behind the installation plate portion 68b and the upper surface portion 261b, and fixed to each of the installation plate portion 68b and the upper surface portion 261b by welding or the like.

[0210] The cam portion 262 has an upper surface portion 262a which is an extension portion to the left from the upper surface portion 261b, a side wall portion 262c which extends downward from the left end of the upper surface portion 262a via a curved corner portion 262b, and a bent portion 262d which is bent to the right from the lower end of the side wall portion 262c. The side wall portion 262c is a portion which is aligned in the up-down direction and has a plate thickness direction in the left-right direction, and has a shape in which the dimension in the width direction (front-rear direction) gradually narrows from the top to the bottom. The lower end portion of the side wall portion 262c is located below the support upper surface portion 71.

[0211] The driving cam 201 acts on the scraper device 200 by bringing the cam portion 262 into contact with the driven roller 208 of the scraper device 200. For this reason, the driving cam 201 is provided so as to cause the cam portion 262 to interfere with the driven roller 208 of the scraper device 200 in the standby position at a predetermined timing in the process in which the hole opening device 40 rises from the lower end position. The driving cam 201 brings the corner portion 262b of the cam portion 262 into contact with the driven roller 208 of the scraper device 200 in the standby state from the lower right side, and receives contact with the driven roller 208 at a left wall surface 262e of the side wall portion 262c.

[0212] The driving cam 201 collides with the driven roller 208 in such a manner that the cam portion 262 strikes the driven roller 208 with the upward momentum of the hole opener 40. The scraper device 200 in the standby position rotates about the rotation axis C1 (see arrow G1 in FIG. 21) by receiving the collision action of the driving cam 201 at the driven roller 208, and causes the scraper 202 to act on the hole opener 40.

[0213] The operation of the hole opening device 40 and the scraper device 200 having the above-mentioned configuration will be described with reference to Figures 24 to 29. In each of Figures 24 to 29, Figure A is a left side view, and Figure B is a rear view.

[0214] 24A and 24B show the state where the hole opening device 40, which moves up and down in conjunction with the rotation of the rotary case 42 about the fulcrum shaft 46, is at the lower end position. At the lower end position, the hole opening device 40 is in an open state with a pair of planting claws 45 open in a vertical posture, and a claw space portion S1 is formed between the mating surfaces 45a of the front and rear planting claws 45 (see FIG. 24A). Regarding the rotational movement of the rotary case 42, as shown in FIG. 24A and FIG. 24B, the case rotation angle at the timing when the hole opening device 40 is at the lower end is set to 0°, and the rotation position of the rotary case 42 at the same timing is set to the reference position. When the case rotation angle is 0°, the scraper device 200 is in a standby state, and the three scrapers 202 are retracted from the operating range of the hole opening device 40 so as not to interfere with the operating range of the hole opening device 40 that moves up and down.

[0215] 25A and 25B show a state where the case rotation angle is 90°. In this state, the hole opening device 40 rises from the lower end position while maintaining the pair of planting claws 45 in an open state as the rotary case 42 rotates and assumes a forward tilting posture due to the guide action of the lift guide 43 and the operation of the arm 44. When the case rotation angle is 90°, the drive cam 201 is located directly below the driven roller 208 (see FIG. 25B), and the scraper device 200 maintains a standby state.

[0216] 26A and 26B show a state where the case rotation angle is 105°. In this state, the hole opening device 40 is raised from a state where the case rotation angle is 90° while maintaining the pair of planting claws 45 in an open state and tilting forward.

[0217] The state where the case rotation angle is 105° is the state immediately after the driving cam 201 collides with the driven roller 208 (see FIG. 26B). In other words, this state is the state immediately after the scraper device 200 starts to rotate from the standby position to the rotation end position. Therefore, the driving cam 201 collides with the driven roller 208 from below at a predetermined timing when the case rotation angle becomes from 90° to 105°.

[0218] When the driving cam 201 collides with the driven roller 208, the scraper device 200 starts to rotate around the rotation axis C1 in a direction to bring the scrapers 202 closer to the hole opening device 40, that is, in the counterclockwise direction when viewed from the rear (see arrow H1 in FIG. 26B). The scraper device 200 rotates from the standby state against the biasing force of the return spring 128. When the scraper device 200 starts to rotate around the rotation axis C1 from the standby position, the three scrapers 202 start to approach the hole opening device 40.

[0219] 27A and 27B show a state where the case rotation angle is 115°. In this state, the hole opening device 40 is slightly raised from the state where the case rotation angle is 105° while maintaining the pair of planting claws 45 in an open state and tilting forward.

[0220] The state where the case rotation angle is 115° is the state where the scraper device 200 reaches the rotation end position. The driven roller 208, which has been in contact with the corner portion 262b of the driving cam 201, comes into contact with the wall surface 262e of the cam portion 262 as the hole opening device 40 rises, and the scraper device 200 reaches the rotation end position (see FIG. 23). When the case rotation angle is 115°, the driven roller 208 is in contact with the upper end portion of the wall surface 262e. The scraper device 200 stops at the rotation end position by abutting the rotation end position stopper 236 against the wall surface portion 112c of the lower bracket 112 (see FIG. 22). That is, the scraper device 200 is sandwiched between the lower bracket 112 and the driving cam 201 in the rotation end state.

[0221] As in the above-described embodiment, the scraper device 200 rotates over a fulcrum about the scraper support shaft 115 located between the movable side support pin 132 and the fixed side support pin 131 by moving the movable side support pin 132, which engages one end of the return spring 128, from the standby state to the rotation end state.

[0222] When the case rotation angle is 115°, the inner scraper 202A is inclined downward to the right in rear view, and most of the inner scraper 202A, except for the tip, is located inside the front and rear planting claws 45. As shown in FIG. 27B, when the inner scraper 202A enters the open hole opening device 40, it is parallel or approximately parallel to the direction of the tangent M1 to the curved portion on the lower left side of the planting claw 45 in rear view. In other words, the inner scraper 202A enters the hole opening device 40 with its plate surface facing the hole opening device 40. When the case rotation angle is 115°, the inner scraper 202A has its tip (lower end) protruding to the lower right side of the lower end of the hole opening device 40 (see FIG. 27B).

[0223] The inner scraper 202A enters the inter-claw space S1 between the front and rear planting claws 45 of the open hole opening device 40, cleaning the inside of each planting claw 45. In detail, the inner scraper 202A acts on the inside of the front and rear planting claws 45 while elastically deforming the surrounding portion of the support part for the scraper arm 207, cleaning in a manner of sweeping the inside of the front and rear planting claws 45. Here, since the inner scraper 202A is supported rotatably with respect to the scraper arm 207, it appropriately elastically deforms and rotates due to the contact resistance with each part of the hole opening device 40.

[0224] Similarly, when the case rotation angle is 115°, the front scraper 202B has its plate surface aligned in the left-right direction and inclined backward in side view, with its tip in contact with the lower surface of the front planting claw 45. The rear scraper 202C has its plate surface aligned in the left-right direction and inclined forward in side view, with its tip in contact with the lower surface of the rear planting claw 45. Here, the front scraper 202B and the rear scraper 202C have their tips aligned with the convex curved surface of the planting claw 45 by the recess 202d.

[0225] The front scraper 202B cleans the outside of the front planting claw 45 for the hole opening device 40 in the open state. In detail, the front scraper 202B acts on the outer surface of the front planting claw 45 while elastically deforming the fin-shaped portion facing the rear side, and cleans in a manner of sweeping the outside of the front planting claw 45. The rear scraper 202C cleans the outside of the rear planting claw 45 for the hole opening device 40 in the open state. In detail, the rear scraper 202C acts on the outer surface of the rear planting claw 45 while elastically deforming the fin-shaped portion facing the front side, and cleans in a manner of sweeping the outside of the rear planting claw 45.

[0226] 28A and 28B show a state where the case rotation angle is 135°. In this state, the hole opening device 40 is raised from the state where the case rotation angle is 115° while maintaining the pair of planting claws 45 in an open state and tilting forward.

[0227] When the case rotation angle is 135°, the scraper device 200 is maintained in its rotation end state. That is, as the hole opener 40 rises from the case rotation angle of 115°, the wall surface 262e of the cam portion 262 contacted by the driven roller 208 functions as a guide surface for the driven roller 208, and the scraper device 200 is maintained in its rotation end state until the case rotation angle reaches approximately 135°. When the case rotation angle is 135°, the driven roller 208 is in contact with the lower end of the wall surface 262e.

[0228] As the case rotation angle changes from 115° to 135°, the three scrapers 202 maintain their position and descend relative to the rising hole opener 40, thereby sweeping downward against the front, inside, and rear of the hole opener 40.

[0229] 29A and 29B show a state where the case rotation angle is 155°. In this state, the hole opening device 40 is raised from the state where the case rotation angle is 135° while maintaining the pair of planting claws 45 in an open state and tilting forward.

[0230] The state where the case rotation angle is 155° corresponds to the timing when the scraper device 200 returns from the rotation end position to the standby position. The scraper device 200 stops at the standby position by abutting the standby position side stopper 235 against the contact plate 239. In the process of the scraper device 200 returning from the rotation end position to the standby position, the three scrapers 202 pass below the raised hole opening device 40.

[0231] Thereafter, as in the above-described embodiment, the hole opener 40 rises to receive seedlings from the seedling supply unit 4, and then descends to plant the seedlings. Note that the trajectory of the hole opener 40 when descending is positioned forward of the trajectory when ascending, so that when the hole opener 40 descends, the driving cam 201 passes in front of the driven roller 208 and does not interfere with the driven roller 208. From the state where the case rotation angle is 0° (see Figures 24A and 24B), the hole opener 40 is cleaned by the scraper device 200 as described above.

[0232] The seedling transplanter 1 equipped with the hole opener 40 and scraper device 200 that perform the above-mentioned operations has the following configuration. That is, the drive cam 201 moves the three scrapers 202 from the retracted position to the cleaning position acting on the hole opener 40 in conjunction with the upward movement of the hole opener 40.

[0233] The retracted position of the scraper 202 is the position of the scraper 202 in the scraper device 200 in the standby state, and is a position retracted from the operating range of the hole opener 40. The cleaning position of the scraper 202 includes a position at the end of rotation, and is a position in a state where the scraper 202 is performing a cleaning action on the hole opener 40, and is a position within a predetermined moving range.

[0234] Particularly, in this embodiment, the driving cam 201 is provided so as to move the scraper 202 from the retracted position to the cleaning position by the upward movement of the hole opener 40. That is, since the driving cam 201 is provided on the hole opener 40 side, the upward movement of the hole opener 40 acts on the driven roller 208, the scraper device 200 rotates, and the scraper 202 moves to the cleaning position.

[0235] Also, similarly to the above-described embodiment, the scraper device 200 is configured to advance and retreat the scrapers 202 from one side in a direction perpendicular to the opening and closing direction of the hole opener 40 in a plan view. That is, the scraper device 200 rotates around the rotation axis C1 to advance the three scrapers 202 located below the rotation axis C1 from the left side to the right side of the hole opener 40 at the front, inner, and rear positions of the hole opener 40 in the open state, thereby cleaning the hole opener 40. Then, the three scrapers 202 that have cleaned the hole opener 40 move to the left side and retreat from the hole opener 40 due to the rotation of the scraper device 200 returning to the standby position.

[0236] According to the seedling transplanter 1 of this embodiment having the above-mentioned configuration, as in the above-mentioned embodiment, the scraper device 200 for removing soil and the like adhering to the hole opener 40 has a relatively simple configuration, which allows it to obtain good tracking ability with the hole opener 40 as it moves up and down, and to perform accurate operation synchronized with the operation of the hole opener 40.

[0237] As the hole opener 40 ascends, the scraper device 200 rotates by receiving the impact of the driving cam 201, which ascends and descends integrally with the hole opener 40, at the driven roller 208, and operates to push the three scrapers 202 into the open hole opener 40. With such a simple configuration, it is easy to synchronize the rotational movement of the scraper device 200 with the ascending and descending movement of the hole opener 40, and the scraper device 200 can be operated with accurate timing. Furthermore, good follow-up to the ascending and descending movement of the hole opener 40 can be obtained, so the scraper device 200 can be operated accurately even with respect to the hole opener 40 that operates at high speed.

[0238] Moreover, the driving cam 201 is provided so as to act on the scraper device 200 by the hole opener 40 ascending from the lower end position, thereby moving the scraper 202 from the retreated position to the cleaning position. With this configuration, the operation timing of the scraper device 200 in response to the ascending and descending movement of the hole opener 40 can be reliably synchronized without being affected by play in the drive system such as the elevating mechanism 41. This allows the scraper device 200 to enter the hole opener 40 from the side to clean it without interfering with the hole opener 40.

[0239] In addition, in the configuration provided with the return spring 128, the scraper device 200 is configured to cross the fulcrum of the scraper support shaft 115 during the rotation between the standby position and the rotation end position. With this configuration, the action of the scraper 202 acting on the hole opener 40 can be assisted by the biasing force of the return spring 128, so that the scraper 202 can be reliably acted on the hole opener 40, and the phase shift of the hole opener 40 due to the reaction force to the drive cam 201 and the deterioration of the durability of the hole opener 40 can be suppressed. In addition, in the rotation of the scraper device 200 returning from the rotation end position to the standby position, the action (biasing force) in the return direction by the return spring 128 decreases near where the return spring 128 crosses the fulcrum, so the configuration of crossing the fulcrum does not hinder the removal of soil and the like attached to the hole opener 40 by the scraper 202. Here, although the return action of the return spring 128 decreases near the fulcrum, the scraper device 200 can achieve good operability in the rotational movement in the direction returning to the standby position due to the action of its own weight.

[0240] The front scraper 202B and the rear scraper 202C are arranged at an angle so as to descend toward the opposing side (hole opening device 40 side) in a side view, and approach the hole opening device 40 from the diagonally lower left side toward the diagonally upper right side in a rear view (see Figs. 26B and 27B). With this configuration, the scraper 202 is easily deformed along the outer circumferential surface of the planting claw 45, so that the scraper 202 can effectively clean the front, rear, and outside of the hole opening device 40.

[0241] In addition, the inner scraper 202A is provided so as to enter the hole opening device 40 from the lower left side of the hole opening device 40 with the plate surface facing the hole opening device 40 side. With this configuration, the inner scraper 202A can be brought into contact with the left edge-shaped portion of the front and rear planting claws 45 and enter the hole opening device 40 while being curved in top view. This allows the inner scraper 202A to reliably act on the inside of the hole opening device 40. In addition, the inner scraper 202A moves downward relative to the hole opening device 40 as the hole opening device 40 rises while positioned in the hole opening device 40. This allows the soil inside the hole opening device 40 to be discharged downward to the outside of the hole opening device 40.

[0242] Moreover, the inner scraper 202A is rotatably attached to the scraper arm 207. With this configuration, the inner scraper 202A can be rotated in accordance with the contact resistance of the inner scraper 202A with the hole opening device 40, so that the inner scraper 202A can be prevented from getting caught or turned over when entering the hole opening device 40.

[0243] In addition, according to the seedling transplanter 1 of this embodiment, the same effects as those of the above-mentioned embodiments can be obtained by the configuration corresponding to the above-mentioned embodiments.

[0244] [Aircraft horizontal control mechanism and its operation unit] The horizontal control mechanism of the machine body of the seedling transplanter 1 and its operating unit will be described with reference to Figs. 1 and 30 to 37.

[0245] The seedling transplanter 1 is equipped with a rolling mechanism that tilts the machine body in the left-right direction. The rolling mechanism rotates the front wheel support arm 17 and the chain case 18 on the right side of the machine body and the front wheel support arm 17 and the chain case 18 on the left side of the machine body in opposite directions by extending and retracting the rolling cylinder 301 (see FIG. 1) provided on the machine body frame 6, changing the height from the bottom ends (ground contact points) of the left and right front wheels 7 and rear wheels 8 to the bottom surface of the machine body (bottom surface of the machine body frame 6), thereby tilting the machine body left and right.

[0246] As shown in FIG. 1, the rolling cylinder 301 is disposed on the left side of the left frame plate 6a of the vehicle frame 6, with the extension direction along the front-rear direction in a plan view and with a front-up inclined shape. As shown in FIG. 30, the rolling cylinder 301 is disposed via a cylinder stay 303 on a support boss 302, which is a cylindrical member disposed in the front of the vehicle frame 6 with the left-right direction as the central axis direction. The support boss 302 is fixed to the front side of a support plate 322 fixed to the tip side of a rod 321a of a vehicle height adjustment cylinder 321 disposed between the left and right frame plates 6a. The vehicle height adjustment cylinder 321 is disposed in such a manner that the extension direction is the front-rear direction and the rod 321a side is the front side.

[0247] A horizontal shaft 304 with its axis extending in the left-right direction is inserted into the support boss 302 so as to be rotatable relative to the support boss 302. Both ends of the horizontal shaft 304 protrude from the support boss 302 and protrude outwardly to the left and right from the left and right frame plates 6a through long holes 6b that are long in the front-rear direction. A cylinder stay 303 is fixed to the end of the left side (the right side in FIG. 30) of the support boss 302 via a stay (not shown). The cylinder stay 303 has a side wall portion 303a with its thickness direction extending in the left-right direction, and the horizontal shaft 304 passes through the side wall portion 303a. A cylindrical boss portion 303b through which the horizontal shaft 304 passes is provided on the left side of the side wall portion 303a of the cylinder stay 303.

[0248] An inner flange portion 304a and an outer flange portion 304b, each with its thickness direction being in the left-right direction, are fixedly provided to the left end of the horizontal shaft 304. The outer flange portion 304b is provided at the left end of the horizontal shaft 304, and the inner flange portion 304a is provided to the right of the outer flange portion 304b. Both the inner flange portion 304a and the outer flange portion 304b include portions that protrude upward from the horizontal shaft 304.

[0249] The rolling cylinder 301 has a rear end (base end) supported rotatably with the left-right direction as the rotation axis direction relative to the rear end of the cylinder stay 303, and a front end (tip end) supported rotatably with the left-right direction as the rotation axis direction relative to a portion of the inner flange portion 304a that protrudes upward from the horizontal shaft 304. The rolling cylinder 301 and the cylinder stay 303 move integrally with the support boss 302 in the front-rear direction of the vehicle body as the vehicle height adjustment cylinder 321 expands and contracts.

[0250] The front end of a lower rod 305 provided on the left side of the rolling cylinder 301 is rotatably connected to the portion of the outer flange portion 304b that protrudes upward from the horizontal shaft 304 (see FIG. 1). The rear end of the lower rod 305 is rotatably connected to a lower support arm 306a that extends downward from the left cylindrical axle case of the rear wheel drive shaft 20. The left axle case of the rear wheel drive shaft 20 is a part that rotates integrally with the left chain case 18.

[0251] An upper rod 300 is provided above the lower rod 305 when viewed from the left side (see FIG. 1). A rear end of the upper rod 300 is rotatably connected to an upper support arm 306b extending upward from an axle case of the rear wheel drive shaft 20. A front end of the upper rod 300 is rotatably connected to a support arm 309 extending upward from a cylindrical axle case on the left side of the front wheel support shaft 16. The left axle case of the front wheel support shaft 16 is a part that rotates integrally with the left front wheel support arm 17.

[0252] On the right side of the vehicle frame 6, similarly to the left side of the vehicle frame 6, a lower rod is provided whose rear end is connected to a lower support arm extending from the right axle case of the rear wheel drive shaft 20 and whose front end is connected to a flange portion provided on the right end of the horizontal shaft 304, and an upper rod whose rear end is connected to an upper support arm extending from the right axle case of the rear wheel drive shaft 20 and whose front end is connected to a support arm extending from the right axle case of the front wheel support shaft portion 16 (both are not shown). However, the lower rod on the right side of the vehicle frame 6 has its front end rotatably connected to a portion of the outer flange portion of the horizontal shaft 304 that protrudes downward from the horizontal shaft 304.

[0253] The rolling cylinder 301 is a double-acting hydraulic cylinder, and switches the flow path of hydraulic oil pumped from a hydraulic pump 307 provided on the machine frame 6 by a rolling cylinder switching valve 308 serving as a switching drive means (see FIG. 30). The hydraulic pump 307 is provided between the engine 12 and the transmission case 15 on the machine frame 6 (see FIG. 1).

[0254] The valve body 308a (see FIG. 30) of the rolling cylinder switching valve 308 can take three positions: a position where the rolling cylinder 301 is extended (extended position), a position where the rolling cylinder 301 is retracted (retracted position), and a position where the flow of hydraulic oil within the rolling cylinder 301 is restricted so that the rolling cylinder 301 is neither extended nor retracted (neutral position).

[0255] In the above configuration, when the rolling cylinder 301 extends, the horizontal shaft 304 rotates counterclockwise in a left side view, and the lower rod 305 on the left side of the vehicle body is pulled toward the front of the vehicle body. As a result, the left axle case of the rear wheel drive shaft 20 rotates clockwise in a left side view, and the upper rod 300 on the left side of the vehicle body is pulled toward the rear of the vehicle body, and the left axle case of the front wheel support shaft 16 rotates clockwise in a left side view. In other words, the front wheel support arm 17 and the chain case 18 on the left side of the vehicle body rotate clockwise in a left side view. On the right side of the vehicle frame 6, when the horizontal shaft 304 rotates counterclockwise as viewed from the left side, the lower rod is pushed toward the rear of the vehicle and the upper rod is pushed toward the front of the vehicle, causing the right axle cases of the rear wheel drive shaft 20 and the front wheel support shaft 16 to rotate in the opposite direction to the axle case on the left side of the vehicle frame 6, and the front wheel support arm 17 and chain case 18 on the right side of the vehicle to rotate counterclockwise as viewed from the left side. That is, when the rolling cylinder 301 extends, the front wheel support arm 17 and chain case 18 on the left side of the vehicle rotate clockwise as viewed from the left side, and the front wheel support arm 17 and chain case 18 on the right side of the vehicle rotate counterclockwise as viewed from the left side, causing the vehicle to tilt so that the left side rises. Conversely, when the rolling cylinder 301 contracts, the vehicle tilts so that the left side falls. In this way, the front wheel support arm 17 and chain case 18 on the left side of the vehicle and the front wheel support arm 17 and chain case 18 on the right side of the vehicle rotate in opposite directions as the rolling cylinder 301 expands and contracts, causing the vehicle to tilt left and right.

[0256] The above-mentioned rolling mechanism is used for horizontal control to keep the machine body horizontal, for example, in an inclined farm field, etc. The horizontal control in the seedling transplanter 1 will be described with reference to FIG.

[0257] As shown in FIG. 30, the seedling transplanter 1 is equipped with a weight 310 for horizontal control. The weight 310 has a rectangular parallelepiped shape and is disposed to the right of the front-rear middle part of the frame plate 6a on the right side of the machine frame 6. The weight 310 is fixed to the lower end of a rotating arm 311 extending in the vertical direction. The vertical middle part of the rotating arm 311 is supported by a support shaft 313 with the front-rear direction as the rotation axis direction with respect to a stay 312 extending from the hydraulic pump 307 to the right so as to be rotatable in the left-right direction. As a result, the rotating arm 311 rotates around the support shaft 313 together with the left-right swing of the weight 310 accompanying the left-right tilt of the machine body.

[0258] One end (right end) of a link 315 extending in the left-right direction is rotatably connected to the upper end of the pivot arm 311, and one end (upper end) of an L-shaped arm 316 is rotatably supported to the other end (left end) of the link 315. A bent portion of the L-shaped arm 316 is rotatably supported by a stay 317 extending leftward from the hydraulic pump 307. The upper end of an arm 318 is rotatably supported to the other end (left end) of the L-shaped arm 316, and the upper end of a valve body 308a extending upward from the rolling cylinder switching valve 308 is rotatably supported to the lower end of the arm 318. The valve body 308a is provided so as to slide in the vertical direction in the rolling cylinder switching valve 308. The link 315, the L-shaped arm 316, the stay 317, and the arm 318 constitute a link mechanism 320 connecting the pivot arm 311 and the valve body 308a.

[0259] In the above-described configuration, when the aircraft body tilts left or right, the weight 310 and the rotating arm 311 swing, and the valve body 308a is displaced via the link mechanism 320. When the aircraft body is in a horizontal state, the rotating arm 311 supporting the weight 310 is vertical, and the position of the valve body 308a is in a neutral position.

[0260] When the machine body tilts downward to the right, the weight 310 and the rotating arm 311 rotate in a direction that moves the weight 310 away from the machine body to the right (see arrow K1 in FIG. 30). As a result, the valve body 308a moves downward via the link mechanism 320 (see arrow K2 in FIG. 30), the position of the valve body 308a becomes a contracted position, the rolling cylinder 301 contracts, and the left side of the machine body lowers. Then, as the machine body becomes horizontal, the weight 310 returns to a position that makes the rotating arm 311 vertical, and the valve body 308a returns to a neutral position via the link mechanism 320.

[0261] On the other hand, when the machine body tilts downward to the left, the weight 310 and the rotating arm 311 rotate in a direction that brings the weight 310 closer to the machine body located to the left (see arrow K3 in FIG. 30). As a result, the valve body 308a moves upward via the link mechanism (see arrow K4 in FIG. 30), the position of the valve body 308a becomes the extended position, the rolling cylinder 301 extends, and the right side of the machine body lowers. Then, as the machine body becomes horizontal, the weight 310 returns to a position that makes the rotating arm 311 vertical, and the valve body 308a returns to a neutral position via the link mechanism. In this way, the attitude of the machine body in the left-right direction is automatically maintained in a horizontal state according to the inclination of the machine body.

[0262] In the seedling transplanter 1 having the configuration for performing the above-described horizontal control of the machine body, a horizontal control operation unit 330 is provided for switching the horizontal control state between "automatic," "fixed," and "manual" states (see Figures 2 and 31).

[0263] The "automatic" state of horizontal control is a state in which left and right movement (swing) of the weight 310 due to its own weight accompanying the left and right tilt of the aircraft, etc., is permitted, and automatic horizontal control as described above is performed. The "fixed" state of horizontal control is a state in which left and right movement of the weight 310 due to its own weight is restricted and horizontal control is disabled, and automatic horizontal control as described above is not performed. The "manual" state of horizontal control is a state in which left and right movement of the weight 310 is performed by operating a specified operating unit, and the configuration for performing horizontal control is operated manually.

[0264] The horizontal control operation unit 330 is provided on the right side of the front-rear extension part 25a on the right side of the handle frame 25, and is disposed near the right front side of the control unit 5. The horizontal control operation unit 330 is configured to switch the horizontal control state to any one of "automatic", "fixed" and "manual" states by operating an operation lever 331 extending to the right in a predetermined direction.

[0265] The operating lever 331 extends rightward from the rear end (base end) of an operating rod 332 that extends horizontally along the front-rear direction of the vehicle body. The operating rod 332 is made of a straight bar-shaped member, with its rear end positioned directly below and near the inner left-right side (left side) of the front-rear extension 25a on the right side of the handle frame 25, and extends forward, with the front end positioned above the weight 310.

[0266] The rear end of the operating rod 332 is supported so as to be movable in the axial direction relative to the support surface portion 26a and rotatable about its axis in a state in which the rear end of the operating rod 332 penetrates the support surface portion 26a that is bent downward on the right rear side of the connecting plate 26 and has a plate thickness direction in the front-rear direction. A circular hole portion 26b (see FIG. 33) is formed in the support surface portion 26a, through which the rear end of the operating rod 332 penetrates.

[0267] The front end (tip) of the operation rod 332 is supported by the rod support arm 334 so as to be movable in the axial direction and rotatable about the axis while passing through the rod support arm 334. The rod support arm 334 is a portion provided in a fixed state on the machine frame 6 side, and is provided in a fixed state with respect to, for example, the hydraulic pump 307 mounted on the machine frame 6. The rod support arm 334 has a plate-like portion with the plate thickness direction in the front-rear direction, through which the operation rod 332 passes, and a circular hole 334a is formed in the tip (right end) of the rod support arm 334 so as to pass the front end of the operation rod 332 through.

[0268] In this manner, the operating rod 332, whose rear end and front end are supported by the support surface portion 26a and the rod support arm 334, is supported so as to be movable in the axial direction and rotatable about its axis as a whole while maintaining its height position and left-right position. The axial movement and axial rotation of the operating rod 332 are performed by operating an operating lever 331 provided integrally with the operating rod 332 as a switching operation of the state of the horizontal control configuration.

[0269] A locking arm 333 is provided near the front end of the operating rod 332 via an arm support bracket 335. The arm support bracket 335 has a rectangular plate-shaped support arm portion 335a with the vertical direction as the longitudinal direction. The support arm portion 335a is fixed to the operating rod 332 by welding or the like with the operating rod 332 passing through the upper end thereof.

[0270] The arm support bracket 335 has a cover portion 335c provided via a connection portion 335b extending forward and upward from the right side of the vertical midpoint of the support arm portion 335a. The cover portion 335c is a bent plate-like portion having a right side surface portion and an upper surface portion, and these surfaces form a substantially "L"-shaped cross section. The cover portion 335c covers, from the right and above, the front end protruding portion 332a of the operating rod 332, which is the portion protruding forward from the support arm portion 335a.

[0271] The locking arm 333 is provided in a hanging manner from the front end of the operating rod 332 together with the support arm portion 335a of the arm support bracket 335, and is located in front of the rotating arm 311 supporting the weight 310. The locking arm 333 has an arm main body portion 333a, which is a plate-shaped portion with the plate thickness direction in the front-rear direction and extends in the up-down direction in a side view, almost entirely except for the lower end. The locking arm 333 overlaps the upper end of the arm main body portion 333a with the front side of the support arm portion 335a, and is fixed to the support arm portion 335a at two points, upper and lower, by bolts 336. The bolts 336 pass through the arm main body portion 333a and the support arm portion 335a, and are screwed into the nut portion 337 provided on the rear side of the support arm portion 335a.

[0272] With the above-described configuration, the operating rod 332, the arm support bracket 335 and the locking arm 333 move together in accordance with the axial movement (front-to-back direction) of the operating rod 332, and rotate together in accordance with the rotation of the operating rod 332 around its axis.

[0273] A hook portion 333b that serves as a locking portion for the rotating arm 311 is formed at the lower end of the locking arm 333. The hook portion 333b is provided as a portion that is bent at a right angle toward the rear side with respect to the arm body portion 333a of the locking arm 333. The locking arm 333 is provided so that the hook portion 333b is positioned above the upper surface 310a of the weight 310 in the up-down direction.

[0274] The lower arm portion 311a forming the lower part of the rotating arm 311 is a narrow plate-like portion extending in the up-down direction with its thickness direction being in the left-right direction, and its lower end portion is fixed to the right side surface 310b of the weight 310 by welding or the like. The rotating arm 311 has a horizontal support side portion 311b bent at a right angle from the upper end of the lower arm portion 311a toward the left, and an upper arm portion 311c forming the upper part of the rotating arm 311 is provided on the support side portion 311b. The upper arm portion 311c is a plate-like portion extending in the up-down direction with its thickness direction being in the front-rear direction, its upper portion is supported by the support shaft 313, and its upper end portion is rotatably connected to the right end portion of the link 315.

[0275] For such a rotating arm 311, the locking arm 333 has a slit-shaped notch 333c in the hook portion 333b that is open at the rear and extends in the front-rear direction as a portion for engaging the lower arm portion 311a. The notch 333c has a width dimension that is slightly larger than the plate thickness dimension (left-right dimension) of the lower arm portion 311a. The hook portion 333b has a left piece 333d and a right piece 333e that are bifurcated to form the notch 333c. The left piece 333d and the right piece 333e form a guide recess 333f behind the notch 333c, the dimension of the left-right distance (the distance between them) gradually increasing from the front side to the rear side.

[0276] The locking arm 333 moves backward together with the operating rod 332, and the lower arm portion 311a is positioned (inserted) into the notch 333c, thereby engaging with the pivot arm 311 (see FIG. 37). In a state in which the locking arm 333 is engaged with the pivot arm 311 (hereinafter, the locking arm 333 is referred to as an "engaged state"), the left and right rotation of the pivot arm 311 and the weight 310 relative to the locking arm 333 is restricted. In other words, in the engaged state of the locking arm 333, the left and right rotation of the pivot arm 311 and the weight 310 is restricted unless the locking arm 333 rotates in conjunction with the rotation of the operating rod 332 about its axis. In other words, when the locking arm 333 is in the engaged state, the pivot arm 311 and the weight 310 pivot left and right together with the locking arm 333 which pivots left and right as the operating rod 332 pivots about its axis.

[0277] The operating lever 331 is composed of a rod-shaped member having a predetermined bent shape. The operating lever 331 has, in order from the base end side (left side) to the tip end side (right side), a lever base 331a, a lever inclined part 331b, and a lever grip part 331c as parts forming a predetermined bent shape. The lever base 331a is a part extending rightward from the right side of the outer circumferential surface of the operating rod 332, and is a part whose axial direction is the left-right direction. The lever inclined part 331b is a part extending from the right end part of the lever base 331a obliquely upward and rearward in a right side view and obliquely rearward to the right in a plan view. The lever grip part 331c is a part extending rightward from the right end part of the lever inclined part 331b, and is a part whose axial direction is the left-right direction. A cap 331d made of rubber or the like is attached to the tip part of the lever grip part 331c.

[0278] The horizontal control operation unit 330 is provided with a guide member 340 for guiding the operation of the operation lever 331. The guide member 340 is a bent plate-like member, and has a fixed surface portion 341 which is a horizontal upper surface portion, and a guide surface portion 342 which is a side surface portion formed by bending at a right angle downward from the right side of the fixed surface portion 341. The guide member 340 is provided in a fixed state with respect to a support bracket 345 which is fixed to the front-rear extension portion 25a of the handle frame 25.

[0279] The support bracket 345 is a U-shaped channel steel member, and is provided with the open side of the U-shape facing left. The support bracket 345 has the front-rear extension 25a positioned between the left ends of the parallel upper surface 345a and lower surface 345b, and is fixed to the front-rear extension 25a by welding or the like. The seedling carrier support frame 33 is fixed and supported by a bolt 346, with the reduced diameter portion 33a forming the lower end of the seedling carrier support frame 33 penetrating the upper surface 345a and lower surface 345b of the support bracket 345. The bolt 346 penetrates the right side surface 345c of the support bracket 345, and the tip of the bolt 346 is in contact with the outer circumferential surface of the reduced diameter portion 33a of the seedling carrier support frame 33, thereby fixing the seedling carrier support frame 33 to the support bracket 345.

[0280] The guide member 340 has a fixing surface portion 341 overlapped from above with an upper surface portion 345a of the support bracket 345, and is fastened to the support bracket 345 by a bolt 347 and a nut 348 (see FIG. 34). The bolt 347 passes through the fixing surface portion 341 and the upper surface portion 345a, and is screwed into the nut 348 below the upper surface portion 345a. The upper surface portion 345a and the lower surface portion 345b of the support bracket 345 and the fixing surface portion 341 of the guide member 340 have a circular opening through which the reduced diameter portion 33a of the seedling tray support frame 33 passes.

[0281] The guide member 340 also has a rod support surface portion 343, which is a surface portion bent downward at a right angle from the rear side of the fixed surface portion 341. The rod support surface portion 343 is a plate-like portion with the plate thickness direction being the front-rear direction, and extends from the fixed surface portion 341 toward the lower left like an arm, with the rear end portion of the operating rod 332 penetrating through it. The rod support surface portion 343 is located near the rear of the support surface portion 26a of the connecting plate 26, and forms a circular hole portion 343a through which the operating rod 332 passes. The rod support surface portion 343 supports the rear end portion of the operating rod 332 so as to be movable in the axial direction and rotatable about the axis.

[0282] The guide member 340 has a guide opening 350 in the guide surface portion 342 that guides the movement of the operating lever 331. The guide opening 350 is formed by cutting out the guide surface portion 342 with the rear side open. The operating lever 331 has the lever base 331a positioned in front of the reduced diameter portion 33a of the seedling tray support frame 33, and the lever gripping portion 331c positioned at the upper right rear of the lever base portion 331a by the lever inclination portion 331b, and the lever gripping portion 331c is positioned within the guide opening 350. In other words, the lever gripping portion 331c penetrates the guide surface portion 342 by the guide opening 350 and protrudes to the right from the guide surface portion 342.

[0283] The guide opening 350 has, as paths for moving the operating lever 331, a first path portion 351 along the front-rear direction, a second path portion 352 extending obliquely upward from the front side of the first path portion 351, and a third path portion 353 formed on the rear side of the first path portion 351 and constituting an opening on the rear side of the guide opening 350. These path portions form openings that are continuous with each other.

[0284] The first path portion 351 has a guide direction for the operating lever 331 in the front-rear direction, and has a constant or approximately constant path width dimension (vertical dimension) larger than the outer diameter of the lever grip portion 331c of the operating lever 331. The second path portion 352 has a guide direction for the operating lever 331 in a front-upward inclination direction, and has the same or approximately the same path width as the first path portion 351. The second path portion 352 is continuous with the front side of the first path portion 351, and is inclined at an angle of approximately 45° with respect to the vertical direction. The first path portion 351 and the second path portion 352 form a path portion bent at an obtuse angle with a constant or approximately constant path width.

[0285] The third path portion 353 is a portion that is continuous with the rear side of the first path portion 351 and has a vertical dimension of the guide opening 350 that is wider on both the top and bottom sides than the path width of the first path portion 351, and is formed as a recess with the rear side open. The vertical direction of the third path portion 353 is the guide direction of the operating lever 331. In other words, the third path portion 353 is a portion that guides the operating lever 331 by allowing the operating lever 331 to rotate up and down accompanied by the rotation of the operating rod 332 around the axis.

[0286] The operating rod 332 is biased forward by the elastic force of the spring 355. The spring 355 is a compression coil spring, and is provided in a state in which the spring 355 penetrates the rear end portion of the operating rod 332 with the axial direction of the operating rod 332 being the extension / contraction direction.

[0287] The spring 355 is interposed in a compressed state between the rod support surface portion 343 of the guide member 340 and a spring seat 356 which is a brim-shaped portion fixed in the vicinity of the rear end portion of the operating rod 332. That is, the rear end portion of the spring 355 abuts against the front side of the rod support surface portion 343, and the front end portion abuts against the rear side of the spring seat 356. Therefore, the support surface portion 26a of the connecting plate 26 located between the rod support surface portion 343 and the spring seat 356 in the front-rear direction has a hole portion 26b through which the operating rod 332 penetrates, the hole portion 26b having a hole diameter through which the spring 355 penetrates together with the operating rod 332.

[0288] In this configuration in which the spring 355 is provided for the operating rod 332, as the operating rod 332 moves rearward, the spring seat 356 moves rearward and approaches the rod support surface portion 343, and the spring 355 contracts.

[0289] The guide surface portion 342 of the guide member 340 is provided with a detent 360 as an engagement portion that acts on the lever gripping portion 331c located inside the guide opening 350 to restrict the forward movement of the operating lever 331. The detent 360 is a cylindrical member made of an elastic material such as rubber, and is provided on the inside (left side) of the guide surface portion 342 at a position above the front-rear middle portion of the first path portion 351 of the guide opening 350, with the central axis direction being the left-right direction. The detent 360 has a shape in which a middle portion in the central axis direction of the cylindrical outer shape is a reduced diameter portion, and both ends in the central axis direction are flange-shaped expanded diameter portions relative to the reduced diameter portion (see FIG. 34).

[0290] The detent 360 is provided in a state of being fitted onto a detent support shaft 361 that penetrates the guide surface portion 342. The detent support shaft 361 is a rod-shaped pin having a disk-shaped head 361a, and penetrates the guide surface portion 342 with the head 361a positioned on the right side of the guide surface portion 342. The detent 360 is supported on the detent support shaft 361 so as to be rotatable about its axis, with the detent support shaft 361 penetrating the inward protruding portion of the guide surface portion 342. A split pin 362 for preventing the detent 360 from coming off is provided on the portion of the detent support shaft 361 that protrudes leftward from the detent 360, penetrating the detent support shaft 361 in the radial direction.

[0291] The detent 360 is provided with respect to the guide opening 350 such that its lower end protrudes from the upper edge 351a of the first path portion 351 in a right side view. In other words, the detent 360 disposed on the upper side of the first path portion 351 has a lower end as a protruding portion 360a protruding downward from the upper edge 351a of the first path portion 351. The protruding portion 360a is a lower end of an enlarged diameter portion at both left and right ends of the detent 360, and has a protruding shape (protruding shape) that forms a circular arc convex downward in a right side view. The protruding portion 360a locally narrows the path width (dimension in the vertical direction) in the first path portion 351 with respect to the operation lever 331 that penetrates the guide opening 350.

[0292] The detent 360 is provided so as to restrict the movement of the operating lever 331 in the front-rear direction in the first path portion 351 in a natural state where it is not elastically deformed. When the operating lever 331 passes through the detent 360 by moving in the front-rear direction in the first path portion 351, the operating lever 331 is sandwiched between a lower edge portion 351b of the first path portion 351 and a protruding portion 360a of the detent 360, and passes through while temporarily crushing and rotating the detent 360. In other words, when the operator moves the operating lever 331 in the front-rear direction in the first path portion 351 with an operating force of a certain level or more, the detent 360 is pushed by the operating lever 331, undergoes compressive deformation, and rotates to allow the operating lever 331 to pass through.

[0293] In this configuration in which the detent 360 acting on the operating lever 331 is provided, the operating lever 331 is positioned on the rear side of the detent 360 in the first path portion 351, and is urged forward by the spring 355, so that the lever gripping portion 331c abuts against the protruding portion 360a of the detent 360, and is restricted from moving forward. This maintains the operating lever 331 in contact with the detent 360 from the rear side.

[0294] The operation for switching the state of horizontal control in the above-mentioned configuration will now be described.

[0295] 32 to 35 show the state in which the horizontal control is in the "automatic" state. In the "automatic" state, the operating lever 331 is biased forward by the spring 355 via the operating rod 332, and is held in a state in which the lever gripping portion 331c is engaged with the corner portion of the first path portion 351 and the second path portion 352 of the guide opening portion 350 (see FIG. 35).

[0296] In the "automatic" state, the operating rod 332 is positioned at the front side within its range of forward and backward movement, and as shown in Fig. 32, the hook portion 333b of the locking arm 333 is positioned in front of the lower arm portion 311a of the rotating arm 311, and is in a state (disengaged state) where it is not engaged with the rotating arm 311. Therefore, in the "automatic" state, the weight 310 is free to move left and right due to its own weight in accordance with the left and right tilt of the aircraft body, and the automatic horizontal control as described above is performed.

[0297] From the “automatic” state, the horizontal control is switched to the “fixed” state by pulling the operating lever 331 toward yourself and moving it backward against the force of the spring 355 (see arrow N1 in FIG. 36A) until it overcomes the detent 360 and then releasing the operating force.

[0298] 36A shows a state in which the horizontal control is "fixed." In the "fixed" state, the operating lever 331 is held in a state in which the lever grip portion 331c abuts against the protruding portion 360a of the detent 360 at the rear end portion of the first path portion 351 while receiving a forward biasing force from the spring 355 via the operating rod 332. Also, in the "fixed" state, the operating lever 331 is located in the first path portion 351 and the vertical movement of the operating lever 331 is restricted, so that the rotation of the operating rod 332 about its axis due to the vertical operation of the operating lever 331 is restricted.

[0299] By changing from the "automatic" state to the "fixed" state, as shown in FIG. 37, the locking arm 333 moves backward together with the operating lever 331 and the operating rod 332 (see arrow Q1) and enters an engaged state. That is, in the "fixed" state, the operating rod 332 is located at the rear side in the range of its forward and backward movement, and the locking arm 333 engages the hook portion 333b with the lower arm portion 311a of the rotating arm 311, entering an engaged state. In addition, in the "fixed" state, the rotating arm 311 becomes vertical, and the weight 310 is in a neutral position. Thus, in the "fixed" state, the axial movement and rotation around the axis of the operating rod 332 are restricted via the operating lever 331, and the left and right movement of the weight 310 due to its own weight is restricted by the locking action of the locking arm 333 fixed to the operating rod 332, and the automatic horizontal control as described above is not activated.

[0300] From the “fixed” state, the horizontal control is switched to the “manual” state by pulling the operating lever 331 toward yourself and moving it backward against the force of the spring 355 (see arrow N2 in Figure 36B) to position the operating lever 331 in the third path portion 353.

[0301] Fig. 36B shows the state in which the horizontal control is in the "manual" state. In the "manual" state, the operating lever 331 is positioned in the third path section 353 by the operating force of the operator pulling it backward against the biasing force of the spring 355. In this state, the third path section 353 allows the operating lever 331 to be moved up and down. In the "manual" state, the engaged state of the locking arm 333 is maintained, as in the "fixed" state (see Fig. 37).

[0302] In the "manual" state, the left and right movement of the weight 310 for horizontal control can be performed by operating the operation lever 331. Specifically, in the "manual" state, by operating the operation lever 331 upward (see arrow P1 in FIG. 36B), the operation rod 332 rotates leftward (counterclockwise) when viewed from the rear, and the rotating arm 311 and the weight 310 rotate in a direction that moves the weight 310 away from the body to the right (see arrow K1 in FIG. 30). Therefore, such an operation of the operation lever 331 is an operation to lower the left side of the body by the operation of the rolling cylinder switching valve 308, the rolling cylinder 301, etc. as described above.

[0303] On the other hand, in the "manual" state, by operating the operating lever 331 downward (see arrow P2 in FIG. 36B), the operating rod 332 rotates rightward (clockwise) when viewed from the rear, and the rotating arm 311 and the weight 310 rotate in a direction that brings the weight 310 closer to the machine body located to the left of it (see arrow K2 in FIG. 30). Therefore, such an operation of the operating lever 331 is an operation that lowers the right side of the machine body by the operation of the rolling cylinder switching valve 308, the rolling cylinder 301, etc. as described above.

[0304] In the "manual" state, by releasing the operating lever 331, the weight 310 returns to the neutral position, and the lever grip portion 331c of the operating lever 331 is brought into a horizontal state, and the biasing force of the spring 355 automatically brings the operating lever 331 into contact with the detent 360, and the horizontal control is switched to the "fixed" state (see FIG. 36A). Also, by moving the operating lever 331 forward from the "fixed" state with an operating force of at least a certain level, the operating lever 331 overcomes the detent 360, and the operating lever 331 automatically moves forward due to the biasing force of the spring 355, and the horizontal control is switched to the "automatic" state. That is, the operating rod 332 moves forward, and the locking arm 333 is disengaged (see arrow Q2 in FIG. 37).

[0305] According to the configuration equipped with the above-described horizontal control mechanism of the machine body and the horizontal control operation unit 330 as its operating unit, by providing an operating rod 332 and an operating lever 331 on a locking arm 333 that engages with the pivoting arm 311 supporting the weight 310 for automatic horizontal control, the horizontal control operation unit 330 can be laid out as a hand-held operation unit for the operator who operates the seedling transplanter 1 using the control unit 5.

[0306] Furthermore, with such a layout configuration of the operating lever 331 by the horizontal control operation unit 330, it is possible to prevent the operating lever 331 from interfering with other operating levers, etc., in a relatively small seedling transplanter 1, and good operability can be obtained for the operating lever 331. In particular, with a configuration in which the operating lever 331 protrudes horizontally toward the right of the machine body, it does not get in the way of other operating levers, etc., and good operability can be obtained for the operating lever 331.

[0307] Moreover, when the horizontal control is in the "manual" state, the weight 310 can be arbitrarily operated by operating the operating lever 331. In particular, the horizontal control operation structure according to this embodiment is configured such that, in a configuration in which the operating lever 331 is extended horizontally, an upward rotation operation of the operating lever 331 corresponds to an operation of lowering the body to the left, and a downward operation of the operating lever 331 corresponds to an operation of lowering the body to the right. With such a configuration, it is possible to easily grasp the correspondence between the lever operation and the movement of the body in an intuitive manner, for example, as in the operation of a turn signal in an automobile, and good operability can be obtained. Furthermore, with the horizontal control operation structure according to this embodiment, manual horizontal control is possible with a simple structure without using wires or the like.

[0308] Furthermore, according to the configuration in which the operating rod 332 is biased by the spring 355, it is possible to reduce the operating load of the operating lever 331 by selecting the spring 355 or the like, thereby reducing the fatigue of the operator.

[0309] Furthermore, according to the configuration in which the operating rod 332 is biased by the spring 355, when the operating lever 331 is released with the operating lever 331 positioned behind the detent 360, the operating lever 331 can be automatically held in a position corresponding to the "fixed" state. This makes it possible to automatically fix the weight 310 in a neutral position. Also, by a simple operation of sliding the operating lever 331 forward from the "fixed" state, the engagement of the operating lever 331 can be released to set it to the "automatic" state in which automatic level control is performed. In this way, the level control can be easily switched between manual, fixed, and automatic by manually operating the operating lever 331.

[0310] Further, a detent 360 that elastically deforms while rotating is provided for the operating lever 331 as a structure for holding the lever position. With such a structure, the detent 360 can be made to function with respect to the operating lever 331 only by the load due to the elastic force of the detent 360, with a simple structure without using a spring or the like. This makes it possible to reduce the operating load of the operating lever 331, and to reduce the fatigue of the operator.

[0311] [Soil cover scraper structure] The scraper structure of the soil covering wheel 95 of the seedling transplanter 1 will be described with reference to Figs.

[0312] As described above, a pair of left and right soil covering wheels 95 are provided behind the seedling planting device 3, supported by a soil covering wheel support frame 96 (see FIG. 1). Each soil covering wheel 95 is provided with a scraper 401 for removing soil, mud, etc. adhering to the soil covering wheel 95. The scrapers 401 and their support structures provided for the left and right soil covering wheels 95 are configured symmetrically.

[0313] As shown in Figures 38 to 41, the left and right soil cover wheels 95 are supported by a support stay 402 provided on the underside of a frame rear edge portion 96a, which is the rear edge portion of a soil cover wheel support frame 96 configured to be approximately "U" shaped, via a soil cover wheel support arm 403 that is approximately "U" shaped. The axial direction of the frame rear edge portion 96a is aligned with the left-right direction of the machine body. A lift lever 404 is provided at the left-right center of the frame rear edge portion 96a for vertically rotating the soil cover wheel support frame 96 that supports the pair of soil cover wheels 95. The lift lever 404 is formed of a straight rod-shaped member and extends rearward from the frame rear edge portion 96a.

[0314] The support stay 402 is a plate-like member that extends in the left-right direction and has a plate thickness direction that is approximately in the front-rear direction, and its left-right middle part is fixed to the frame rear edge part 96a by welding or the like. The support stay 402 as a whole has a gently curved shape that convexes forward with the left-right center part as a bent part, and both left and right sides are extension parts 402a that are spaced away from the frame rear edge part 96a and extend outward to the left and right and slightly diagonally backward.

[0315] The soil cover wheel support arm 403 has a fixed portion 403a, which is the upper side, and a pair of arm portions 403b extending downward from the fixed portion 403a, and is configured in a generally "U" shape by these portions. The soil cover wheel support arm 403 has a shape in which a narrow plate-like member having a predetermined width is bent. The fixed portion 403a is located above the soil cover wheel 95 and extends in a direction parallel to the axle direction of the soil cover wheel 95. The arm portions 403b are portions bent from both ends of the fixed portion 403a so as to form a right angle with the fixed portion 403a. The pair of arm portions 403b face each other as parallel surfaces.

[0316] The soil cover wheel support arm 403 is fixed to the front side of both the left and right sides including the extension portion 402a of the support stay 402. The soil cover wheel support arm 403 is fixed to the support stay 402 by welding or the like, with the rear end face 403c of the fixing portion 403a serving as a contact face for the front face 402b of the support stay 402 (see FIG. 42).

[0317] The soil cover wheel support arm 403, with the fixed portion 403a fixed to the support stay 402 in this manner, has a pair of arm portions 403b extending downward from the support stay 402. The soil cover wheel support arm 403 positions the soil cover wheel 95 between the pair of arm portions 403b, and supports the soil cover wheel 95 rotatably by an axle 405 installed between the lower ends of the pair of arm portions 403b. The axle 405 is composed of a bolt-shaped member, penetrates the arm portion 403b, the soil cover wheel 95, and the arm portion 403b from the left and right outer sides, and is screwed into a nut 406 at the protruding portion from the left and right inner arm portion 403b. The soil cover wheel 95 has a thick, approximately disc-shaped outer shape, and has an outer peripheral surface portion 95a that serves as a ground contact surface, and left and right side portions 95b.

[0318] The scraper 401 is located at the upper rear side relative to the soil cover wheel 95. The scraper 401 is a plate-like member having a predetermined curved shape, and has a scraper main body 411 having a substantially rectangular plate-like outer shape when viewed from the rear, and side plate portions 412 provided on both the left and right sides of the scraper main body 411.

[0319] The scraper 401 is provided so that the lower edge 411a of the scraper body 411 is aligned with the outer peripheral surface 95a of the soil cover wheel 95 with a small gap 413 (see FIG. 40). The dimension X1 of the gap 413 is the size of the distance between the lower edge 411a and the outer peripheral surface 95a in the radial direction of the soil cover wheel 95, and is about several millimeters (for example, 1 mm or 2 mm). However, the size of the gap 413 may be zero. The scraper 401 provided on the rear upper side of the soil cover wheel 95 is provided in an inclined state so that the distance from the outer peripheral surface 95a of the soil cover wheel 95 to the lower edge 411a of the scraper body 411 gradually increases from the upstream side to the downstream side of the rotation direction of the soil cover wheel 95 (from the bottom side to the top side in FIG. 40) so that the lower edge 411a faces the rotation direction of the soil cover wheel 95 when the machine body moves forward (see arrow Y1 in FIG. 40). In this way, the scraper 401 is arranged so that the lower edge 411a of the scraper main body 411 faces the rotational direction of the soil cover wheel 95, and is inclined so that the scraper main body 411 forms an acute angle with the tangent to the circumferential shape formed by the outer peripheral surface 95a of the soil cover wheel 95 when viewed from the side (when viewed in the axial direction of the axle 405), making it easier to remove soil and the like adhering to the soil cover wheel 95 and improving soil drainage inside the scraper 401.

[0320] The side plate portions 412 are provided on both the left and right sides of the lower portion of the scraper main body 411 as bent surfaces relative to the scraper main body 411, so as to fit along the side surface portion 95b of the soil cover wheel 95. The side plate portions 412 have a substantially rectangular outer shape with the direction of extension from the scraper main body 411 as the longitudinal direction, and are provided so that the longitudinal direction is aligned with the radial direction of the soil cover wheel 95. The side plate portions 412 are provided against the outer periphery of the side surface portion 95b of the soil cover wheel 95.

[0321] The side plate portion 412 is provided such that a lower edge portion 412a, which is continuous with a lower edge portion 411a of the scraper main body portion 411 in a curved shape, is aligned with the outer periphery of the side portion 95b of the soil cover wheel 95 with a small gap 414 therebetween. The lower edge portion 412a is the lower long side portion of the rectangular side plate portion 412. The gap 414 is set to a size of about several millimeters, similar to the gap 413 in the scraper main body portion 411.

[0322] As described above, the scraper 401 is provided with the lower edges 411a, 412a of the scraper body 411 and the left and right side plate parts 412 aligned with the outer peripheral surface part 95a and the outer peripheral parts of the side parts 95b on both sides that form the outer periphery of the soil cover wheel 95, and with small gaps 413, 414 between the scraper and the soil cover wheel 95. The scraper 401 acts by moving relative to the soil cover wheel 95 that rotates as the machine advances, and scrapes off and removes soil and the like that has adhered to the outer peripheral surface part 95a and the side parts 95b of the soil cover wheel 95. The scraper body 411 of the scraper 401 has two rectangular holes 411b formed on the left and right at the bottom. The holes 411b are through-holes for passing soil and the like.

[0323] The scraper 401 is provided in a state in which it is supported by a scraper support frame 420 relative to the soil cover wheel support arm 403. The scraper support frame 420 is configured to be substantially U-shaped with the front side open, and is provided to extend from the upper part of the soil cover wheel support arm 403 toward the rear side.

[0324] The scraper support frame 420 has, as a substantially "U" shaped portion, left and right support frame portions 421 and a rear fixed frame portion 422 which is a portion between the rear ends of the left and right support frame portions 421. The scraper support frame 420 has a form obtained by bending a narrow plate-like member.

[0325] In this embodiment, the scraper support frame 420 is composed of two frame members: a first frame member forming the rear of the left and right inner support frame parts 421, a fixed frame part 422, and the left and right outer support frame parts 421, and a second frame member forming the left and right outer support frame parts 421. The first frame member and the second frame member are fixed to each other at two points by a bolt 423 that penetrates the overlapping part of the left and right outer support frame parts 421. The bolt 423 is screwed into a nut part 424, which is a welded nut provided on the inside of the surface part forming the left and right outer support frame parts 421 of the first frame member. The scraper support frame 420 may be composed of an integral, approximately "U" shaped member.

[0326] The scraper support frame 420 is supported by pins 425 with the front ends of the left and right support frame parts 421 overlapping the upper parts of the left and right arm parts 403b of the soil cover wheel support arm 403 from the outside. The pins 425 penetrate the support frame parts 421 and the arm parts 403b, and are engaged by clip pins or the like (not shown) on the inside of the support frame parts 421. The scraper support frame 420 is supported by the soil cover wheel support arm 403 so as to be rotatable about a straight line passing through the central axes of the left and right pins 425 as a rotation axis R1. The rotation axis R1 is parallel to the rotation center line of the soil cover wheel 95 by the axle 405, and is located above this rotation center line. The support frame parts 421 extend rearward from the pivot part by the pins 425 perpendicular to the longitudinal direction of the arm parts 403b.

[0327] The scraper 401 is attached to the fixed frame portion 422 of the scraper support frame 420. The scraper 401 is fixed to the scraper support frame 420 at two points, left and right, by bolts 426 with the upper part of the scraper main body portion 411 overlapping the fixed frame portion 422 from the rear side. The bolt 426 penetrates the scraper main body portion 411 and the fixed frame portion 422, and is screwed into a nut portion 427, which is a welded nut provided on the inside (front side) of the fixed frame portion 422. The scraper main body portion 411 is formed with a hole portion 411c through which the bolt 426 penetrates. The hole portion 411c is an elongated hole with the left-right direction as the longitudinal direction, and the attachment position of the scraper 401 relative to the fixed frame portion 422 can be adjusted in the left-right direction.

[0328] As described above, the scraper 401 is attached to the scraper support frame 420 which is supported by the left and right pins 425 on the soil cover wheel support arm 403, and is provided so as to be rotatable together with the scraper support frame 420 around the axis of rotation R1. By the scraper 401 rotating together with the scraper support frame 420 around the axis of rotation R1, the distance of the scraper 401 to the soil cover wheel 95, that is, the size of the gap 413 between the lower edge portion 411a of the scraper main body portion 411 and the outer peripheral surface portion 95a of the soil cover wheel 95 (FIG. 40, dimension X1) changes. In the following, the integral rotating body including the scraper support frame 420 and the scraper 401 supported so as to be rotatable around the axis of rotation R1 is referred to as the "scraper unit 410."

[0329] With respect to rotation about the rotation axis R1, the scraper unit 410 is biased in a direction in which the scraper 401 approaches the soil cover wheel 95 by a spring 430 provided between the support stay 402 and the scraper support frame 420. The scraper support frame 420 has spring support frame parts 440 in front of the support frame parts 421 on the left and right outer sides as parts for supporting the springs 430.

[0330] The spring support frame parts 440 are parts extending forward from the left and right outer support frame parts 421, and have a side part 441, a front part 442, and a spring support surface part 443. The side part 441 is a plate-like part extending upward at a right angle from the front side of the pivot support part by the pin 425 of the left and right outer support frame parts 421. The front part 442 is a plate-like part bent at a right angle from the front side of the side part 441 toward the left and right inner sides.

[0331] The spring support surface portion 443 is a plate-like portion bent at a right angle from the upper end portion of the front surface portion 442 toward the rear side. The spring support surface portion 443 is located in front of the left and right ends of the support stay 402, and a protruding edge portion which is an edge portion on the rear side faces the extension portion 402a. In this embodiment, the spring support frame portion 440 is provided as a part of the second frame member which constitutes the scraper support frame 420, and the side surface portion 441 forms a flat surface portion which is continuous with the support frame portions 421 on the left and right outer sides.

[0332] The spring 430 is a coil spring having hook-shaped locking portions at both ends, and is installed between the left and right ends of the support stay 402 and the spring support surface portion 443 of the spring support frame portion 440 with the expansion and contraction direction being approximately the front-rear direction. The spring 430 is installed in a state in which the rear hook portion 431, which is the rear locking portion, is locked in the rear locking hole 402c formed in the left and right ends of the support stay 402, and the front hook portion 432, which is the front locking portion, is locked in the front locking hole 444 formed in the spring support surface portion 443. The rear locking hole 402c penetrates the support stay 402 in the plate thickness direction. The front locking hole 444 penetrates the spring support surface portion 443 in the plate thickness direction.

[0333] The spring 430 is a tension spring, and biases the scraper unit 410 in a direction (see arrow T1 in FIG. 40) that brings the spring support surface portion 443 closer to the support stay 402 when the scraper unit 410 rotates around the rotation axis R1. Hereinafter, with regard to the rotation direction of the scraper unit 410 around the rotation axis R1, the direction in which the scraper 401 approaches the soil cover wheel 95, that is, the direction in which the gap 413 between the lower edge portion 411a of the scraper main body portion 411 and the outer peripheral surface portion 95a of the soil cover wheel 95 is narrowed (see arrow U1 in FIG. 40), is referred to as the "scraper approaching direction," and the opposite direction, that is, the direction in which the gap 413 is widened (see arrow U2 in FIG. 40), is referred to as the "scraper separating direction."

[0334] In a configuration in which the scraper unit 410 is rotatably supported while being biased by the spring 430 in the scraper approaching direction, a stopper bolt 450 that restricts the rotation of the scraper unit 410 in the scraper approaching direction is provided on the spring support frame portion 440. The stopper bolt 450 restricts the rotation of the scraper unit 410 in the scraper approaching direction so that the scraper main body portion 411 of the scraper 401 does not come into contact with the outer peripheral surface portion 95a of the soil cover wheel 95, that is, so that a gap 413 is maintained.

[0335] The stopper bolt 450 penetrates the front part 442 of the spring support frame part 440 from the front side, and the tip surface 451, which is the rear end surface, abuts against the front surface 403d of the left and right outer ends of the fixing part 403a of the soil cover wheel support arm 403. By the stopper bolt 450 provided on the scraper support frame 420 side abutting against the soil cover wheel support arm 403 in this manner, the rotation of the scraper unit 410 in the scraper approach direction is restricted, and the gap 413 is secured. In the following, the state in which the stopper bolt 450 abuts against the soil cover wheel support arm 403 for the scraper unit 410 is referred to as the "normal state."

[0336] The stopper bolt 450 is screwed into a nut portion 445, which is a welded nut provided on the rear side of the front surface portion 442. By rotating the stopper bolt 450 using the nut portion 445, the projection dimension of the stopper bolt 450 from the nut portion 445 to the rear side (the right side in FIG. 42) changes. This changes the position at which the rotation of the scraper support frame 420 in the scraper approaching direction is stopped, that is, the position of the scraper unit 410 with respect to rotation around the rotation axis R1 in the normal state.

[0337] Therefore, by adjusting the axial position of the stopper bolt 450, it is possible to adjust the size of the gap 413 in the normal state of the scraper unit 410. By screwing in the stopper bolt 450 to increase the rearward protruding dimension, the size of the gap 413 in the normal state of the scraper unit 410 increases, and conversely, by moving the stopper bolt 450 forward to decrease the rearward protruding dimension, the size of the gap 413 in the normal state of the scraper unit 410 decreases. A nut 452 for fixing the position of the stopper bolt 450 is screwed into a portion of the stopper bolt 450 forward of the front surface 442.

[0338] The scraper 401 and its support structure described above provide the following effect. When the scraper 401 receives an upward force from soil or the like adhering to the soil cover wheel 95 while the machine body is moving forward, the scraper unit 410 rotates in the scraper moving away direction against the biasing force of the spring 430. The scraper unit 410 that rotated in the scraper moving away direction rotates in the scraper approaching direction due to the biasing force of the spring 430, and returns to a state (normal state) in which rotation is restricted by the stopper bolt 450.

[0339] In the scraper 401 and its support structure as described above, the load (biasing force) applied by the spring 430 to the scraper unit 410 can be adjusted. The spring load by the spring 430 is adjusted by changing the engagement position of the spring 430 relative to the spring support surface portion 443 in the extension / contraction direction of the spring 430. In order to change the engagement position of the spring 430 relative to the spring support surface portion 443, the spring support surface portion 443 is provided with a plurality of front engagement holes 444 for engaging the front hook portions 432 of the spring 430.

[0340] In this embodiment, three front locking holes 444, a first locking hole 444a, a second locking hole 444b, and a third locking hole 444c, are formed from the front side to the rear side in the spring support surface portion 443 (see FIG. 42). These front locking holes 444 are arranged at predetermined intervals in the extension / contraction direction of the spring 430 (left-right direction in FIG. 42). In order to ensure the thickness of the portion between the adjacent front locking holes 444, the second locking hole 444b is formed at a position shifted outwardly to the left and right with respect to the other two front locking holes 444.

[0341] By selecting the front locking hole 444 to lock the front hook portion 432 of the spring 430, the expansion / contraction state of the spring 430 in the normal state of the scraper unit 410 changes, and the load by the spring 430 is adjusted. By locking the front hook portion 432 in the first locking hole 444a, the spring 430 is maximized in the normal state and the load (tensile load) acting on the scraper unit 410 is maximized. The expansion of the spring 430 in the normal state, that is, the load by the spring 430, is maximized when the front locking hole 444 used to support the spring 430 is the first locking hole 444a, and decreases in this order for the second locking hole 444b and the third locking hole 444c.

[0342] That is, with regard to the engagement position of the spring 430 by the front hook portion 432 with respect to the three front engagement holes 444, from the viewpoint of the strength of the load of the spring 430, the engagement position by the first engagement hole 444a is the "strong" position, the engagement position by the second engagement hole 444b is the "medium" position, and the engagement position by the third engagement hole 444c is the "weak" position. Regarding the "weak" position, for example, the position can be set so that the stopper bolt 450 is in a free state in which the biasing force of the spring 430 does not act when it is in contact with the soil cover wheel support arm 403. In the free state, the scraper unit 410 is in a state in which the stopper bolt 450 is in contact with the soil cover wheel support arm 403 by its own weight alone (without receiving the tensile force of the spring 430).

[0343] As described above, the biasing force of the spring 430 against the scraper unit 410 can be adjusted to three stages by the three front locking holes 444. The number of front locking holes 444 may be two or four or more. In addition, as a configuration for adjusting the biasing force of the spring 430, for example, rear locking holes 402c for locking the rear hook portions 431 of the spring 430 in the support stay 402 may be formed at multiple locations at intervals in the extension / contraction direction of the spring 430.

[0344] Regarding the scraper structure of the soil cover wheel 95, for example, a configuration is assumed in which the spring 430 is not provided, and the scraper unit 410 scrapes off soil and the like adhering to the soil cover wheel 95 only by its own weight. With such a configuration, when a highly viscous soil lump or a large soil lump adheres to the soil cover wheel 95, the scraper 401 cannot sufficiently remove the soil lump, and in order to prevent the soil cover wheel 95 from being locked by the soil lump, the soil cover wheel 95 and the scraper 401 must be cleaned manually by an operator at an early stage. This causes a decrease in workability.

[0345] Therefore, the seedling transplanter 1 of this embodiment has a scraper structure for the soil cover wheel 95, in which a scraper unit 410 including a scraper 401 is supported rotatably around a rotation axis R1 relative to the soil cover wheel support arm 403, and the scraper unit 410 is biased in the scraper approach direction by a spring 430. With this configuration, the load of the spring 430 in addition to the weight of the scraper unit 410 can be applied to the soil adhering to the soil cover wheel 95, so that even if soil that is relatively difficult to remove, such as a highly viscous soil lump, is adhering to the soil cover wheel 95, it can be effectively removed by the scraper 401.

[0346] A stopper bolt 450 is provided to restrict the rotation of the scraper unit 410 in the direction approaching the scraper so as to secure a gap 413 between the scraper 401 and the soil cover wheel support frame 96. This makes it possible to always secure a gap of an appropriate size between the scraper 401 and the soil cover wheel support frame 96 according to the soil quality of the field, thereby enabling the scraper 401 to perform a good removal action.

[0347] Furthermore, the spring 430 is provided so that the load acting on the scraper unit 410 can be adjusted by the three front locking holes 444. With this configuration, it is possible to adjust the load acting on the scraper unit 410 by the spring 430 to an appropriate value according to the soil quality of the field and the rotation speed of the soil cover wheel 95 corresponding to the speed of the machine. This reduces the number of times that the worker has to manually clean the soil cover wheel 95, etc., and provides good workability.

[0348] For example, when working in a field where the soil has a relatively high viscosity, such as clay, the first locking hole 444a or the second locking hole 444b is used as the front locking hole 444 for locking the front hook portion 432 of the spring 430, in which the load of the spring 430 is large and the resistance of the scraper 401 against the soil, etc., adhering to the soil cover wheel 95 is relatively large. Also, when working in a field where the soil has a relatively low viscosity, such as sand, the third locking hole 444c is used as the front locking hole 444 for locking the front hook portion 432 of the spring 430, in which the load of the spring 430 is small and the resistance of the scraper 401 against the soil, etc., adhering to the soil cover wheel 95 is relatively small.

[0349] The above-described embodiment is an example of the present invention, and the present invention is not limited to the above-described embodiment. Therefore, even if it is not the above-described embodiment, various modifications are possible according to the design, etc., as long as they do not deviate from the technical idea of ​​the present invention. In addition, the effects described in this disclosure are merely examples and are not limited, and other effects may be present.

[0350] The present technology can have the following configurations. Note that the configurations described below can be selected and combined as desired. (1) A seedling transplanter equipped with a seedling planting device having a seedling planting tool that plants seedlings in a field by lifting and lowering, A cleaning device having a cleaning body acting on the seedling planting tool, and removing soil and the like adhering to the seedling planting tool by the cleaning body; and an actuating member that acts on the cleaning device in association with the upward movement of the seedling planting tool, thereby actuating the cleaning device so that the cleaning body acts on the seedling planting tool. A seedling transplanter characterized by the above. (2) The operating member moves the cleaning body from a retracted position to a cleaning position acting on the seedling planting tool in association with the upward movement of the seedling planting tool. The seedling transplanter according to (1) above, (3) A traveling machine body equipped with the seedling planting device is provided, The seedling planting tool is provided so as to move up and down relative to the traveling body, The cleaning device is configured to move the cleaning body into and out of the seedling planting tool from one side in a direction perpendicular to the opening and closing direction of the seedling planting tool in a plan view. The seedling transplanter according to (1) or (2), characterized in that (4) The cleaning device has a roller that receives the action of the operating member on its outer circumferential surface. The seedling transplanter according to any one of the above items (1) to (3). (5) The cleaning device has, as the cleaning body, an inside cleaning body acting on the inside of the seedling planting tool and an outside cleaning body acting on the outside of the seedling planting tool. The seedling transplanter according to any one of the above items (1) to (4), [Explanation of symbols]

[0351] 1 Seedling transplanter 2 Running body 3 Seedling planting device 9 seedlings 10. Field 40 Hole opener (seedling planting tool) 100 Scraper device (cleaning device) 101 Driving cam (operating member) 102 Scraper (cleaning body) 102A Inner scraper (cleaning body, inner cleaning body) 102B Front scraper (cleaning body, outside cleaning body) 102C Rear scraper (cleaning body, outside cleaning body) 108 Driven roller (roller) 108a Outer surface 200 Scraper device (cleaning device) 201 Driving cam (operating member) 202 Scraper (cleaning body) 202A Inner scraper (cleaning body, inner cleaning body) 202B Front Scraper (Cleaning Body, Outer Cleaning Body) 202C Rear Scraper (Cleaning Body, Outer Cleaning Body) 208 Passive Roller (Roller) 208a Outer Peripheral Surface

Claims

1. A seedling transplanter equipped with a seedling planting device having a seedling planting tool that plants seedlings in a field by lifting and lowering, A cleaning device having a cleaning body acting on the seedling planting tool, and removing soil and the like adhering to the seedling planting tool by the cleaning body; and an actuating member that acts on the cleaning device in association with the upward movement of the seedling planting tool, thereby actuating the cleaning device so that the cleaning body acts on the seedling planting tool. A seedling transplanter characterized by the above.

2. The operating member moves the cleaning body from a retracted position to a cleaning position where the cleaning body acts on the seedling planting tool in accordance with the upward movement of the seedling planting tool.

2. A seedling transplanter according to claim 1.

3. A traveling machine body equipped with the seedling planting device is provided, The seedling planting tool is provided so as to move up and down relative to the traveling body, The cleaning device is configured to move the cleaning body into and out of the seedling planting tool from one side in a direction perpendicular to the opening and closing direction of the seedling planting tool in a plan view.

3. A seedling transplanter according to claim 1 or 2.

4. The cleaning device has a roller that receives the action of the operating member on its outer circumferential surface.

2. A seedling transplanter according to claim 1.

5. The cleaning device has, as the cleaning body, an inside cleaning body acting on the inside of the seedling planting tool and an outside cleaning body acting on the outside of the seedling planting tool.

2. A seedling transplanter according to claim 1.

Images