Seedling transplanter

Abstract

To provide a seedling transplanter which can suppress the interference of a furrow-opening arm with a planted seedling, and can obtain a good planting property.SOLUTION: The seedling transplanter includes a groove-forming arm (200) provided in the vicinity of a planting claw (72) and configured to move relative to the planting claw (72), and a trajectory changing device (270) configured to change a moving trajectory of the groove-forming arm (200) with respect to the planting claw (72) so as to correspond to a seedling planting pitch of the planting claw (72).SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present invention relates to a seedling transplanter that continuously performs seedling planting work in a field using a seedling planting device. [Background technology]

[0002] In a conventional seedling transplanter that continuously plants seedlings in a field using a seedling planting device, a plate-shaped seedling mat placed on a seedling carrier that slopes downward at the rear is fed horizontally and vertically, and the planting claws of the seedling planting device continuously scrape (cut) the seedling mat one piece at a time to plant the seedlings. Some seedling transplanters of this type are equipped with a furrow-making arm that drills transplant holes in a mulch film when planting seedlings with the planting claws and excavates (furrows) transplant holes for transplanting the seedlings into the field (see, for example, Patent Document 1). The mulch film is a film that is applied to the soil in the field to keep it moist and warm, suppress weeds, and so on.

[0003] Patent Document 1 discloses a configuration in which a seedling holding / hole digging arm, which is a furrow-making arm, is attached to the underside of the planting claw via a swinging arm. The seedling holding / hole digging arm has a mulch film hole-punching blade at its tip and is rotatable relative to the planting claw via the swinging arm. The seedling holding / hole digging arm moves together with the potted seedling while supporting it from the bottom after it has been removed by the planting claw. When the potted seedling reaches the field surface, the arm swings backward, using the mulch film hole-punching blade to punch a hole in the mulch film for transplanting and dig a transplant hole in the soil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-330607 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration disclosed in Patent Document 1, the furrowing arm (seedling holding / hole digging arm) is attached to the planting claw via a bracket or the like, and rotates to open the underside of the potted seedling once the potted seedling held by the planting claw reaches the field surface. This configuration reduces the degree of freedom in the relative position of the furrowing arm to the planting claw, making it difficult to accommodate changes in seedling planting conditions, such as changes in the spacing between plants, which affects the position of holes drilled in the mulch film or the digging position of transplant holes in the soil. Note that the spacing between plants refers to the distance between seedlings planted consecutively at a predetermined distance in the front-to-rear direction.

[0006] Insufficient response to changes in seedling planting conditions can result in problems such as reduced seedling planting accuracy, increased furrow torque on the soil, and interference of the furrow arm with planted seedlings. Contact of the furrow arm with planted seedlings can damage the seedlings or worsen their planting position.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a seedling transplanter that can suppress interference of the furrow-making arm with the planted seedlings and achieve good planting performance. [Means for solving the problem]

[0008] The seedling transplanter of the present invention is a seedling transplanter that uses planting claws to cut off a seedling mat placed on a seedling carrier one section at a time and continuously plant the seedlings in a field, and is equipped with a furrow making arm that is located near the planting claws and is adapted to move relative to the planting claws, and a trajectory change device that changes the movement trajectory of the furrow making arm relative to the planting claws to correspond to the seedling planting pitch by the planting claws.

[0009] The seedling transplanter of the present invention is such that, in the seedling transplanter, the furrow making arm is configured to change its position and posture relative to the planting claw in conjunction with the operation of the planting claw.

[0010] In the seedling transplanter of the present invention, the trajectory change device is configured by a link mechanism that supports the furrow making arm relative to the planting claw device including the planting claws.

[0011] In the seedling transplanter of the present invention, the link mechanism includes two link arms, one end of which is rotatably supported on the planting claw device side and the other end of which is rotatably supported on the furrowing arm side, and the trajectory change device changes the movement trajectory of the furrowing arm relative to the planting claws by changing the distance between the support portions of the two link arms on the furrowing arm side.

[0012] In the seedling transplanter of the present invention, the furrow making arm has two relative positions and postures with respect to the planting claws: a standby position which is the position and posture when the planting claws cut the seedling mat, and a furrow making position in which it moves forward relative to the planting claws when planting seedlings in the field, and is configured to perform a cyclical movement from the furrow making position back to the standby position after the planting claws have finished planting seedlings in the field.

[0013] In the seedling transplanter of the present invention, the furrow making arm is configured so that, when in the furrow making position, the tip thereof protrudes forward beyond the planting claws and enters the field surface ahead of the planting claws.

[0014] The seedling transplanter of the present invention is such that the furrow-making arm is arranged so as not to interfere with the seedlings planted in the field, at least within the operating range in which the tip is positioned below the field surface. [Effects of the Invention]

[0015] According to the present invention, in a seedling transplanter, interference of the furrow making arm with the planted seedlings can be suppressed, thereby achieving good planting performance. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a left side view showing the overall configuration of a seedling transplanter according to an embodiment of the present invention. FIG. [Figure 2] 1 is a plan view showing the overall configuration of a seedling transplanter according to an embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing a power transmission configuration of the seedling transplanter according to one embodiment of the present invention. [Figure 4] FIG. 1 is a rear perspective view showing the configuration of a seedling transplanting device according to an embodiment of the present invention. [Figure 5] FIG. 2 is a rear view showing the configuration of the seedling transplanting device according to one embodiment of the present invention. [Figure 6] FIG. 1 is a front perspective view showing the configuration of a seedling planting device according to an embodiment of the present invention. [Figure 7] FIG. 1 is a rear perspective view showing the configuration of the lower part of the seedling transplanting device according to one embodiment of the present invention. [Figure 8] FIG. 1 is a perspective view showing a seedling mat according to one embodiment of the present invention. [Figure 9] FIG. 1 is a plan view showing a seedling mat according to one embodiment of the present invention. [Figure 10] FIG. 2 is a side view showing a seedling mat according to one embodiment of the present invention. [Figure 11] 1 is an oblique view showing the configuration of a guide rail and a planting claw device according to one embodiment of the present invention. FIG. [Figure 12] A left side view showing the configuration of a guide rail and a planting claw device according to one embodiment of the present invention. [Figure 13] A plan view showing the configuration of a guide rail and a planting claw device according to one embodiment of the present invention. [Figure 14] A left side view showing the configuration of the guide rail and the support configuration of the seedling mat relative to the guide rail in one embodiment of the present invention. [Figure 15] FIG. 10 is an explanatory diagram illustrating the seedling mat scraping operation, which is one of the operations of the planting claw device according to one embodiment of the present invention. [Figure 16] FIG. 10 is an explanatory diagram illustrating the planting operation of the seedling block, which is one of the operations of the planting claw device according to one embodiment of the present invention. [Figure 17] FIG. 1 is a perspective view showing an example of a planting unit according to one embodiment of the present invention. [Figure 18] This is a left side view showing the planting claw device, furrow making arm in a furrow making position, and link mechanism according to one embodiment of the present invention. [Figure 19] FIG. 2 is a plan view showing an example of a planting unit according to one embodiment of the present invention. [Figure 20] This is a left side view showing the planting claw device, furrowing arm in a standby position, and link mechanism according to one embodiment of the present invention. [Figure 21] FIG. 1 is a perspective view showing a groove making arm according to an embodiment of the present invention. [Figure 22] FIG. 2 is a left side cross-sectional view showing a portion of a groove making arm according to an embodiment of the present invention. [Figure 23] FIG. 4 is a view showing a cam plate according to one embodiment of the present invention. [Figure 24] An explanatory diagram showing the operation of the groove-making arm accompanying the relative rotation of the planting claw device with respect to the rotary case in one embodiment of the present invention. [Figure 25] An explanatory diagram showing the operation of the groove-making arm accompanying the relative rotation of the planting claw device with respect to the rotary case in one embodiment of the present invention. [Figure 26] An explanatory diagram showing the operation of the groove-making arm accompanying the relative rotation of the planting claw device with respect to the rotary case in one embodiment of the present invention. [Figure 27] An explanatory diagram showing the operation of the groove-making arm accompanying the relative rotation of the planting claw device with respect to the rotary case in one embodiment of the present invention. [Figure 28] An explanatory diagram showing the operation of the groove-making arm accompanying the relative rotation of the planting claw device with respect to the rotary case in one embodiment of the present invention. [Figure 29] FIG. 10 is a graph illustrating the operation of the planting claw device and furrowing arm according to one embodiment of the present invention. [Figure 30] FIG. 10 is an explanatory diagram illustrating the operation of the planting unit according to one embodiment of the present invention. [Figure 31]FIG. 10 is an explanatory diagram illustrating the operation of the planting unit according to one embodiment of the present invention. [Figure 32] FIG. 10 is an explanatory diagram illustrating the operation of the planting unit according to one embodiment of the present invention. [Figure 33] FIG. 10 is an explanatory diagram illustrating the operation of the planting unit according to one embodiment of the present invention. [Figure 34] FIG. 10 is an explanatory diagram illustrating the operation of the planting unit according to one embodiment of the present invention. [Figure 35] FIG. 10 is an explanatory diagram illustrating the operation of the planting unit according to one embodiment of the present invention. [Figure 36] This is a left side view showing the planting claw device, furrow making arm in a furrow making position, and link mechanism according to one embodiment of the present invention. [Figure 37] This is a left side view showing the planting claw device, furrowing arm in a standby position, and link mechanism according to one embodiment of the present invention. [Figure 38] 10A to 10C are explanatory diagrams illustrating the operation of a groove making arm according to one embodiment of the present invention. [Figure 39] FIG. 10 is a diagram showing an example of the movement trajectory of the planting claws and furrowing arm in one embodiment of the present invention. [Figure 40] FIG. 10 is a diagram showing an example of the movement trajectory of the planting claws and furrowing arm in one embodiment of the present invention. [Figure 41] FIG. 10 is a diagram showing an example of the movement trajectory of the planting claws and furrowing arm in one embodiment of the present invention. [Figure 42] FIG. 10 is a left side view showing a planting claw device, a furrow making arm in a furrow making position, and a link mechanism according to another embodiment of the present invention. [Figure 43] FIG. 10 is a plan view showing an example of a planting unit according to another embodiment of the present invention. [Figure 44] FIG. 10 is a left side view showing a planting claw device, a furrowing arm in a standby position, and a link mechanism according to another embodiment of the present invention. [Figure 45] FIG. 10 is a perspective view showing a groove making arm according to another embodiment of the present invention. [Figure 46] FIG. 10 is a left side cross-sectional view showing a portion of a groove making arm according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention aims to improve planting performance by using a planting claw by devising a structure for a furrow-making arm for forming a furrow in a field when planting seedlings with the planting claw. The following describes an embodiment of the present invention.

[0018] The overall configuration of the seedling transplanter 1 according to this embodiment will be described using Figures 1 to 7. In the following description, the left side (lower side in Figure 2) and right side (upper side in Figure 2) when facing the front of the seedling transplanter 1 will be referred to as the left and right sides of the seedling transplanter 1, respectively.

[0019] As shown in Figures 1 and 2, the seedling transplanter 1 according to this embodiment is a riding seedling transplanter that travels with an operator on board to perform seedling planting work, and is used to sequentially transplant vegetable seedlings, such as cabbage, onion, and tomato, into a field. The seedling transplanter 1 comprises a traveling body 2 that constitutes the traveling section, and a seedling transplanting device 3 that constitutes the planting section. The seedling transplanting device 3 is connected to the rear of the traveling body 2 via a link device 4 that includes multiple links so that it can be raised and lowered. The seedling transplanting device 3 rises and falls relative to the traveling body 2 by the operation of a hydraulic cylinder (not shown).

[0020] The traveling machine body 2 has a machine body frame 5, left and right front wheels 6, and left and right rear wheels 7. The machine body frame 5 is configured in a framework shape using multiple frame members, and has a front frame section 11 that forms a horizontal frame portion, and a rear frame section 12 that forms a stepped section that is one step higher on the rear side of the front frame section 11. The left and right front wheels 6 are provided below the front frame section 11, and the left and right rear wheels 7 are provided below and behind the rear frame section 12. The left and right front wheels 6 and the left and right rear wheels 7 support the machine body frame 5 relative to the field.

[0021] A horizontal floor 13 made of a vehicle body cover or the like is provided above the front frame 11 of the traveling body 2. A driver's unit 8 for driving and operating the traveling body 2 and the seedling transplanting device 3 is provided on the floor 13. A seat support base 9, which is a seat mount, is provided in the center of the left and right rear of the driver's unit 8, and a driver's seat 10 is provided on the seat support base 9. A fuel tank (not shown) is provided below the seat 10.

[0022] An operating unit 14 is provided at the front of the floor 13 and is operated by an operator seated in the seat 10. The operating unit 14 is provided with a dashboard 16 on which a steering handle 15 and the like are arranged, located in front of the seat 10, various operating pedals such as a speed change pedal 18, and various operating levers such as a speed change lever and a planting clutch lever. The steering handle 15 is attached to the upper end of a handle support shaft 15a that protrudes upward from the dashboard 16.

[0023] An engine 20 serving as a drive source is provided in the center of the front of the floor 13, in front of and below the steering handle 15 (see FIG. 1). The engine 20 is covered by a hood 17. The engine 20 is mounted via brackets, vibration-isolating rubber, etc. to an engine support frame 21 provided on the lower front side of the front frame 11 (see FIG. 1). The engine support frame 21 includes two front and rear support frames 21a that are U-shaped when viewed from the front. The engine 20 is, for example, a diesel engine, and is provided with the axial direction of its output shaft aligned in the left-right direction.

[0024] A transmission case 22 incorporating a power transmission mechanism including gears, clutches, brakes, etc. is provided behind the engine 20. An HST 23, which is an example of a continuously variable transmission, is attached to the left side of the transmission case 22.

[0025] As shown in Fig. 3, the power of the engine 20 is transmitted from an output shaft 20a of the engine 20 to an input shaft 23a of the HST 23 via a belt transmission mechanism 24 composed of pulleys, a belt, etc. The power transmitted to the input shaft 23a is input from the HST 23 to a power transmission mechanism inside the transmission case 22. Here, "HST" refers to a hydraulic continuously variable transmission that uses a system in which hydraulic pressure generated by driving a hydraulic pump is converted back into rotational force by a hydraulic motor.

[0026] Front axle cases 25 are attached to both the left and right sides of the transmission case 22. A front axle 26 is rotatably supported at the lower end of the front axle case 25, and the front wheels 6 are attached to the portions of the front axle 26 that extend outward on the left and right sides from the front axle case 25. A power transmission mechanism is provided inside the front axle case 25 to transmit the rotational power of the front wheel drive shafts that extend outward on the left and right sides from the transmission case 22 to the front axle 26.

[0027] A rear axle case 28 is provided behind the transmission case 22. The rear axle case 28 receives the power of the transmission case 22 via a transmission shaft 27 extending from the rear of the transmission case 22. The power input from the HST 23 to the power transmission mechanism inside the transmission case 22 drives the transmission shaft 27 to rotate.

[0028] The rear axle case 28 has protruding case sections 28a on both the left and right sides that protrude rearward relative to the case body. A rear axle 29 is rotatably supported by the left and right case sections 28a, and the rear wheels 7 are attached to the portions of the rear axle 29 that extend outward to the left and right from the protruding case sections 28a. A power transmission mechanism is provided within the rear axle case 28 that transmits rotational power input from the transmission case 22 via the transmission shaft 27 to the left and right rear axles 29.

[0029] A PTO output shaft 31, which is a power takeoff shaft, extends rearward from the rear of the transmission case 22. A power transmission mechanism within the transmission case 22 receives power from the HST 23 and drives the PTO output shaft 31 to rotate.

[0030] The rotational power of the PTO output shaft 31 is transmitted to the input shaft 34 of the inter-row transmission case 33 via the PTO transmission shaft 32. The PTO transmission shaft 32 is connected to the PTO output shaft 31 and the input shaft 34 via universal joints or the like. A transmission 36 composed of speed-increasing and reducing gears, a speed change mechanism, etc. is provided inside the inter-row transmission case 33. The power transmitted to the input shaft 34 is changed in speed by the transmission 36 inside the inter-row transmission case 33 and transmitted to the seedling transplanting device 3 by a planting drive shaft 35 extending rearward from the inter-row transmission case 33.

[0031] The seedling transplanting device 3 comprises a planting transmission case 40 incorporating a power transmission mechanism that receives power from the planting drive shaft 35, a seedling carrier 42 mounted on a planting frame 41 connected to the rear side of the link device 4, and a seedling planting device 43 driven by power transmitted from the planting transmission case 40. In this embodiment, a pair of seedling planting devices 43 are provided, one on the left and one on the right. Note that the number of seedling planting devices 43 may be one or three or more.

[0032] A plurality of seedling mats 100 are placed on the seedling carrier 42. The seedling carrier 42 has a surface on its front side (upper rear side) for receiving the seedling mats 100, and the surface is sloped downward at the rear. The seedling transplanter 1 according to this embodiment has a four-row planting configuration and has four seedling carrier sections 46 lined up in the left-right direction. Note that while the illustration shows a state in which a seedling mat 100 is placed on only the second seedling carrier section 46 from the left, in actual planting work, seedling mats 100 are placed on all seedling carrier sections 46.

[0033] Each seedling carrier 46 has a carrier body 46a made of a plate-like member that forms the carrier surface for the seedling mat 100, and low wall-like guide portions 46b provided along the left and right edges of the carrier body 46a. The guide portions 46b are protruding portions of the carrier body 46a that face the carrier surface for the seedling mat 100 and are provided along the entire extension direction of the carrier body 46a. The seedling carrier 42 has a vertical feed structure that intermittently moves the seedling mat 100 set on the carrier body 46a vertically (downward) on the carrier body 46a of each seedling carrier 46.

[0034] Each seedling carrying tray 46 is provided with a feed belt 47. In this embodiment, each seedling carrying tray 46 is provided with two rows of feed belts 47 arranged side by side. The feed belts 47 are endless belts whose feed direction is along the vertical direction when viewed from the rear, and are provided to form the lower part of the tray main body 46a. The feed belts 47 are configured to be driven in a circular motion so as to move the side that receives the seedling mat 100 downward, intermittently feeding the seedling mat 100 vertically.

[0035] A guide rail 48 is provided below the seedling carrier 42, extending linearly in the left-right direction of the machine body. The guide rail 48 is provided along the lower edge of the seedling carrier 42 and is longer than the left-right width of the seedling carrier 42. The guide rail 48 is supported by a predetermined support member and fixed to the planting frame 41 of the seedling transplanting device 3. The guide rail 48 supports the seedling mat 100 placed on the seedling carrier 42 from below.

[0036] The seedling carrier 42 supplies the seedling mats 100 placed on each seedling carrier section 46 to each planting unit. The seedling carrier 42 is configured to reciprocate left and right by a drive mechanism (not shown) to transport the seedling mats 100 laterally (in the width direction of the vehicle). In other words, the seedling carrier 42 is configured to reciprocate left and right relative to the guide rails 48. Furthermore, when the seedling carrier 42 reaches the end of its left and right reciprocating movement, the feed belt 47 sends the seedling mats 100 on each seedling carrier section 46 vertically downward. As the seedling carrier 42 moves left and right, the seedling mats 100 placed on the seedling carrier 42 move along the guide rails 48 while being supported from below by the guide rails 48.

[0037] A horizontal frame 45, which forms part of the planting frame 41, is provided below the seedling carrier 42. The horizontal frame 45 is a linear frame member with a rectangular cylindrical outer shape, and is installed horizontally so as to extend in the left-right direction. The horizontal frame 45 is installed over almost the entire range of the seedling transplanting device 3 in the left-right direction.

[0038] A planting transmission case 40 is provided in the center of the horizontal frame 45. The planting transmission case 40 is provided in an overhanging shape so that its rear portion is positioned behind the horizontal frame 45, and has an overhanging portion to the rear. Left and right seedling planting devices 43 are provided behind the horizontal frame 45. The left and right seedling planting devices 43 are configured symmetrically with respect to the center of the seedling transplanting device 3 in the left-right direction.

[0039] The seedling planting device 43 is a rotary-type planting device and includes a planting transmission case 51, two rotary cases 52 provided on both the left and right sides of the planting transmission case 51, and a planting claw device 50 provided for each rotary case 52. In other words, the seedling transplanting device 3 has four planting claw devices 50 and is compatible with a four-row planting configuration. The rotary cases 52 and planting claw devices 50 on both the left and right sides of the planting transmission case 51 form a planting unit.

[0040] The planting transmission case 51 has a cylindrical outer shape with its longitudinal direction extending in the front-to-rear direction, and its front end is fixed to the rear wall of the horizontal frame 45, extending rearward from the rear side of the horizontal frame 45. A planting transmission shaft 55 with its axial direction extending in the left-to-right direction is provided between the left and right planting transmission cases 51.

[0041] The planting transmission shaft 55 is a shaft formed by coaxially connecting multiple shafts with joints or the like, and is rotatably supported relative to the planting transmission case 40. The planting transmission shaft 55 extends to both the left and right sides from the rear of the planting transmission case 40, and is rotatably supported relative to each planting transmission case 51 at the front of each planting transmission case 51. The planting transmission shaft 55 receives power from a power transmission mechanism provided within the planting transmission case 40. The planting transmission shaft 55 interconnects the power transmission mechanisms within the planting transmission case 40 and the left and right planting transmission cases 51.

[0042] A pair of rotary cases 52 are provided on the left and right sides of the rear of the planting transmission case 51. The rotary cases 52 are rotatably attached to the rear end of the planting transmission case 51 by a drive shaft 52a whose axial direction is in the left-right direction. The rotary case 52 has a longitudinal outer shape, and its central portion in the longitudinal direction is journaled relative to the planting transmission case 51. Planting claw devices 50 are attached to the left and right outer sides of the rotary case 52.

[0043] The planting claw device 50 is supported on one longitudinal end of the rotary case 52 so as to be rotatable about a rotation axis 50a whose rotation axis is in the left-right direction (see Figure 3). The planting claw device 50 is connected to the rotary case 52 so as to be linked to the rotation of the rotary case 52 relative to the planting transmission case 51. The planting claw device 50 is configured to perform a predetermined planting operation in conjunction with the rotation of the rotary case 52. By performing the planting operation, the planting claw device 50 sequentially scrapes off the seedling mat 100 placed on the seedling carrier 42 one by one (one plant at a time) and plants them in the field. As the body of the seedling transplanter 1 moves forward, one planting claw device 50 plants one row of seedlings.

[0044] The guide rail 48 is provided with intake sections 49 that position the portion of the seedling mat 100 to be scraped and ensure a movement path for the planting claw devices 50 (see Figure 13). The intake sections 49 are provided at positions corresponding to each planting claw device 50 in the longitudinal direction of the guide rail 48. Therefore, intake sections 49 are provided at four locations on the guide rail 48. The intake sections 49 are notched sections that are open on the rear side and have a rectangular shape in a plan view.

[0045] The seedling transplanting device 3 configured as described above receives power input from the planting drive shaft 35 in the planting transmission case 40. The drive power input to the planting transmission case 40 is transmitted to the planting transmission shaft 55 by a power transmission mechanism inside the planting transmission case 40. The rotational drive power of the planting transmission shaft 55 is distributed to the left and right seedling planting devices 43 and transmitted to the drive shafts 52a of the rotary cases 52 on both the left and right sides of the planting transmission case 51 via multiple transmission shafts, gears, etc. provided inside the planting transmission case 51. The rotational drive of the drive shafts 52a rotates the left and right rotary cases 52, allowing the planting unit to continuously plant seedlings.

[0046] In the power transmission system of the seedling transplanter 1, the rotational power input to the drive shaft 52a of the rotary case 52 is changed by the HST 23 along with the traveling speed of the traveling body 2 in accordance with the amount of operation of a speed change operating member such as the speed change pedal 18 provided on the driver's unit 8. Therefore, the rotational speed of the rotary case 52, and therefore the planting speed of the seedling transplanter 3, changes according to the traveling speed of the traveling body 2. In detail, the faster the traveling speed of the machine body, the shorter the rotation period of the rotary case 52, and the slower the traveling speed of the machine body, the longer the rotation period of the rotary case 52. As a result, the seedling planting interval (distance between plants) remains constant regardless of the traveling speed of the traveling body 2.

[0047] As shown in Figure 3, the speed change device 36 in the spacing transmission case 33 can change the rotational speed of the rotary case 52, thereby changing the spacing between rows. The spacing between rows is changed depending on, for example, the type of crop being planted and the condition of the field. A planting clutch 37 is provided in the spacing transmission case 33. Operation of the planting clutch 37 connects and disconnects the rotational power from the transmission device 36 to the planting drive shaft 35. The planting clutch 37 is engaged / disconnected by operating a planting clutch lever provided in the driving unit 8. The operation of the planting clutch 37 can also be controlled by a controller provided in the seedling transplanter 1.

[0048] A pair of soil covering wheels 61 is provided on the left and right behind each of the four planting units of the seedling transplanting device 3. The soil covering wheels 61 have a truncated cone shape and are supported so that they can rotate freely, with their outer circumferential surfaces acting as the surface for contact with the field. The pair of soil covering wheels 61 are oriented so that their bottom surfaces face each other, and are inclined so that the underside of the outer circumferential surface of each soil covering wheel 61 is approximately horizontal, forming a roughly "V" shape when viewed from behind.

[0049] The soil covering wheels 61 are supported via support members on the rear edge 62a of a soil covering wheel support frame 62, which is configured in a frame shape to surround the seedling planting device 43 in a plan view. The soil covering wheel support frame 62 is installed with its front end supported on the horizontal frame 45. The pair of soil covering wheels 61 act on the area where the seedlings have been planted by the planting claw device 50 immediately after planting, thereby suppressing the soil.

[0050] The seedling transplanting device 3 is provided with stands 64 on both the left and right sides of the lower part of the planting frame 41 to support the seedling transplanting device 3 relative to the ground. The stands 64 are constructed from pipe-like members bent into a roughly L-shape, with one end supported on the horizontal frame 45 via support fittings or the like so that it can rotate with the front-to-back direction as its axial direction. The stand 64 can be moved from a roughly horizontal stored state to an upright state with one side aligned with the ground, thereby entering a usable state in which it supports the seedling transplanting device 3 relative to the ground. Note that the illustration shows the stand 64 in the stored state, and the stand 64 in the usable state is indicated by a two-dot chain line in Figure 5.

[0051] The seedling mat 100 will be described with reference to Figs. 8 to 10. The seedling mat 100 is formed by sowing a plurality of seeds in a predetermined arrangement. The seeds sown in the seedling mat 100 are, for example, vegetable seeds such as cabbage, onion, and tomato. However, the seeds may also be paddy rice seeds. When planting seedlings using the seedling transplanter 1, the seedling mat 100 is used in a state where the seedlings have grown from the seeds.

[0052] As shown in Figures 8 to 10, the seedling mat 100 has a roughly rectangular plate-like outer shape and is formed in a flat plate shape overall. In the seedling mat 100, the longitudinal direction of the rectangular outer shape in a plan view (the up-down direction in Figure 9) is the vertical direction, and the lateral direction of the same outer shape (the left-right direction in Figure 9) is the horizontal direction. The vertical direction and the horizontal direction are directions that are perpendicular to each other when the seedling mat 100 is viewed in a plan view.

[0053] The seedling mat 100 has one plate surface side as the front surface 101 and the other plate surface side as the back surface 102. The seedling mat 100 has a plurality of front surface grooves 103 formed along the horizontal direction at a predetermined interval in the vertical direction on the front surface 101. The seedling mat 100 has side surfaces 100a which are the surfaces on both sides in the horizontal direction, and end surfaces 100b which are the surfaces on both sides in the vertical direction.

[0054] The front surface groove portion 103 is a V-shaped groove, and is formed by a pair of groove forming surfaces 103a that form a V-shape when viewed from the side of the seedling mat 100. The front surface groove portion 103 is formed so that its depth D1 is, for example, approximately 1 / 3 to 1 / 2 of the thickness T1 of the seedling mat 100. The seedling mat 100 has an outer shape when viewed in the lateral direction (side view) that is approximately constant throughout the lateral direction, and both ends of the front surface groove portion 103 are open to the side surface portion 100a of the seedling mat 100.

[0055] In the seedling mat 100, the portion partitioned by the surface groove portion 103 on the surface portion 101 side becomes the row block portion 104. The row block portion 104 forms a relatively protruding ridge portion on the surface portion 101 side by the surface groove portion 103 on both sides in the vertical direction. A plurality of sowing holes 105 are formed in the row block portion 104 on the surface portion 101 side.

[0056] 8 to 10, the seedling mat 100 is made up of 20 rows of horizontally aligned row block portions 104 connected vertically. In Fig. 10, the boundary between adjacent row block portions 104 is indicated by a virtual line B1.

[0057] In each row block portion 104, a plurality of sowing holes 105 are arranged in a row along the horizontal direction at predetermined intervals. The sowing holes 105 are, for example, holes having a substantially cylindrical shape. One or more seeds are placed in the sowing holes 105. Each row block portion 104 has an upper surface 104a that is aligned with the imaginary plane A1. The sowing holes 105 open toward the upper surface 104a of the row block portion 104.

[0058] The seedlings 106 that grow from the seeds in the sowing holes 105 grow out of the sowing holes 105 and extend from the front surface 101. The seedling mat 100 is formed from a material that allows roots to grow from the seeds in the sowing holes 105 on the back surface 102 side. The material forming the seedling mat 100 includes organic fiber materials, which are fiber materials composed of organic matter. Examples of organic fiber materials include coco peat, peat moss, rice husks, etc. The material forming the seedling mat 100 may also include binders, soil improvement materials, fertilizers, soil, etc. Note that the seedlings 106 are not shown in Figures 8 and 9.

[0059] In the seedling mat 100, the formation area of ​​one sowing hole 105 becomes a unit block portion 108 for one plant that is scraped (cut) at a time by the planting operation of the planting claw device 50. The unit block portion 108 is a roughly square area with the sowing hole 105 at the center in a plan view, and is separated from the seedling mat 100 by being scraped across the entire thickness of the seedling mat 100 by the planting claw device 50 to become a seedling block 110 (see Figure 15C) that is roughly rectangular or cubic in shape. This is merely an example, but the seedling block 110 has a roughly cubic shape with each side measuring approximately 30 mm.

[0060] In the example shown in Figures 8 to 10, ten sowing holes 105 are formed horizontally in each row block portion 104, and each row block portion 104 is made up of ten connected unit block portions 108 that become seedling blocks 110 when scraped off by the planting claw device 50. In Figures 8 and 9, for one row block portion 104 located at the end of the seedling mat 100, the boundary between adjacent unit block portions 108 is shown by a virtual line B2.

[0061] The seedling mat 100 also has a plurality of back grooves 107 formed in the back surface portion 102 along the horizontal direction at predetermined intervals in the vertical direction. The back grooves 107 are formed at positions in the vertical direction corresponding to the front grooves 103. Therefore, the back grooves 107, together with the front grooves 103, shorten the dimension in the thickness direction of the seedling mat 100 (the vertical direction in FIG. 10) of the connecting portions between vertically adjacent row block portions 104.

[0062] The back side groove portion 107 is a U-shaped groove, and is formed by a pair of side surfaces and a curved upper curved surface that form a U-shape when viewed from the side of the seedling mat 100. The back side groove portion 107 is formed so that its depth D2 is, for example, approximately 1 / 4 to 1 / 3 of the thickness T1 of the seedling mat 100. Both ends of the back side groove portion 107 are open to the side surface portion 100a of the seedling mat 100. The shape of the back side groove portion 107 is not limited to a U-shaped groove.

[0063] The row block portions 104 are partitioned on the back surface 102 side of the seedling mat 100 by the back surface groove portions 107 at the same pitch as on the front surface 101 side. On the back surface 102 side, the row block portions 104 form relatively protruding ridges due to the back surface groove portions 107 on both sides in the vertical direction. Each row block portion 104 has a lower surface 104b that is aligned along an imaginary plane A2 that is parallel to the imaginary plane A1.

[0064] The back groove 107 is the portion of the seedling mat 100 placed on the delivery belt 47 that receives the engagement of multiple engagement protrusions 47a (see Figure 7) provided on the delivery belt 47. The protrusions 47a are portions that protrude from the surface of the delivery belt 47 and are formed linearly in the left-right direction. The protrusions 47a have a cross-sectional shape that is, for example, rectangular. The vertical spacing between the multiple protrusions 47a corresponds to the vertical spacing between the multiple back grooves 107 on the seedling mat 100. The back groove 107 is formed slightly wider than the protrusions 47a so that the protrusions 47a can fit into it.

[0065] When the seedling mat 100 is placed on the feed-out belt 47, the protrusions 47a fit into each rear groove 107, thereby locking the seedling mat 100 to the feed-out belt 47. This prevents the seedling mat 100 from slipping relative to the feed-out belt 47, which rotates in a vertical direction, and allows the seedling mat 100 to be reliably fed vertically by the feed-out belt 47. In other words, the seedling carrier 42 can reliably feed the seedling mat 100 vertically toward the guide rail 48 by the feed-out belt 47. Furthermore, the engagement of the protrusions 47a with the rear groove 107 locks the seedling mat 100 against the feed-out belt 47, preventing the seedling mat 100 from being compressed vertically by its own weight.

[0066] The seedling mat 100 described above is scraped off by the planting claw device 50 in the seedling transplanting device 3 and planted in the field as follows: That is, the seedling mat 100 is scraped off sequentially from the unit block portion 108 located at the starting end, which is the end on one side of the row block portion 104 at the lower end, which is the portion supported by the guide rail 48, toward the other side as the seedling carrier 42 moves left or right. That is, during one scraping cycle by the planting claw device 50, the seedling mat 100 moves laterally along the guide rail 48 a distance equivalent to one unit block portion 108, and successively a new unit block portion 108 is positioned above the intake portion 49, which is the scraping position.

[0067] The row block portions 104 at the bottom are successively scraped off from the starting end, and when the terminal unit block portion 108, which is the other end of the row block portion 104 on the left or right side of the row block portion 104, is scraped off, the operation of the feed belt 47 sends the seedling mat 100 one row below the row block portion 104 (longitudinal feeding), and the seedling mat 100 is supported by the guide rail 48 from the end face portion 100b of the row block portion 104, which is now located at the bottom. In other words, the new row block portion 104 is now positioned on the guide rail 48 as the scraped portion. Then, the previous terminal end becomes the starting end, and the seedling mat 100 is moved by the seedling carrier 42, which turns around and moves to the other side, and the unit block portions 108 are successively scraped off.

[0068] In this way, the seedling mat 100 is scraped off at each unit block portion 108 by the planting claw device 50 which rotates in a predetermined trajectory, moving back and forth from bottom to top in the left and right direction, by horizontal feeding due to the left and right reciprocating movement of the seedling carrier 42 and vertical feeding due to the intermittent operation of the delivery belt 47.

[0069] The end surface 100b of the seedling mat 100, which is supported by the guide rail 48, has a groove-forming surface 103a, a groove-forming surface 107a corresponding to approximately half the width of the backside groove 107, and an intermediate surface 109a between the groove-forming surface 103a and the groove-forming surface 107a. Because the seedling mat 100 has a periodic shape in the vertical direction, with the row block portions 104 as units, the shape of the end surface 100b is approximately the same between the lower end surface 100b of the seedling mat 100 before being scraped by the planting claw device 50 and the end surface 100b of the seedling mat 100 after at least one row of row block portions 104 has been scraped off. In the end surface 100b after being scraped by the planting claw device 50, the intermediate surface 109a is the cut surface by the planting claw device 50.

[0070] In this way, the seedling mat 100 used by the seedling transplanter 1 has a surface groove portion 103 on the surface side (surface portion 101 side), which is the surface opposite to the loading surface side of the seedling loading platform 42, which corresponds to the unit of cutting by the planting claws 72 and is a groove portion extending in a direction perpendicular to the vertical feed direction.

[0071] The configuration of the planting claw device 50 will be described using Figures 6 and 11 to 13. For ease of explanation, the furrowing arm 200 and its support mechanism, which will be described later, are omitted from Figures 11 to 13. As shown in Figures 6 and 11 to 13, the planting claw device 50 has an arm portion 71, a planting claw 72 fixed to the arm portion 71, a push-out member 73 movable relative to the arm portion 71, a holding plate 74 as a holding member arranged to face the planting claw 72, a holding plate support portion 75 that supports the holding plate 74, and a digging claw 76 arranged below the holding plate 74.

[0072] The planting claw device 50 has a base 70 as the connection portion to the rotary case 52, and an extension portion in which the arm portion 71, planting claws 72, etc. extend linearly from the base 70 in a predetermined direction, with the tip of the planting claw 72 being the tip of the extension portion. Hereinafter, the direction along the extension direction of the extension portion of the planting claw device 50 (the direction of arrow C1 in Figure 12) will be referred to as the "claw extension direction." In addition, in the planting claw device 50, the tip side of the planting claw 72 in the claw extension direction will be referred to as the front side, and the opposite side will be referred to as the rear side.

[0073] The arm portion 71 is a substantially cylindrical portion whose cylindrical axis direction is the claw extension direction of the planting claw device 50. The arm portion 71 is an integral part of the base portion 70 and extends from the base portion 70 in the claw extension direction.

[0074] The planting claw 72 has a roughly rectangular plate-shaped claw base 81 and two claw main bodies 82 extending in the claw extension direction from one longitudinal side of the claw base 81, with the tip end forked. The planting claw 72 has a roughly constant width overall, with the width direction aligned with the left-right direction and the length direction aligned with the claw extension direction.

[0075] The nail base 81 is a bent plate-like portion having a flat, generally U-shaped cross section, and has a flat portion and sidewall portions on both the left and right sides. The nail main body 82 extends from the upper side of the front end of the nail base 81 in the nail extension direction.

[0076] The planting claw 72 is fixed to the upper side of the arm 71 by two fixing parts provided at intervals in the claw extension direction at the claw base 81. The fixing part of the planting claw 72 is a fastening fixing part in which a nut 84 is screwed onto a male screw part 83 that protrudes upward from the arm 71 and penetrates the flat part of the claw base 81.

[0077] The pair of nail main bodies 82 extend linearly in the nail extension direction from both widthwise edges of the nail base 81. The pair of nail main bodies 82 are formed parallel to each other with a substantially constant gap between them, and a space 85 is formed between the pair of nail main bodies 82.

[0078] Each claw body 82 has a sharpened tip 82a. The pair of claw bodies 82 have a shape that is approximately symmetrical in the left-right direction. Each claw body 82 has an approximately "L"-shaped cross section, consisting of an upper surface 82b and left and right outer side surfaces 82c. The distance between the side surfaces 82c of the left and right claw bodies 82 is approximately the same as the lateral dimension of the seedling block 110. In other words, the lateral dimension of the unit block portion 108 in the seedling mat 100 is approximately the same as the distance between the left and right side surfaces 82c.

[0079] The pusher member 73 is provided on the front side of the arm portion 71 and is adapted to move back and forth along the claw extension direction relative to the arm portion 71. The pusher member 73 is provided below the pair of claw bodies 82 of the planting claws 72. The pusher member 73 has a push rod 86 and a pressing piece 87 provided on the tip side of the push rod 86.

[0080] The push rod 86 is a rod portion that constitutes a cylinder mechanism together with the arm portion 71, with the arm portion 71 serving as a cylinder portion, and extends from the tip of the arm portion 71 in the claw extension direction. The push rod 86 moves back and forth relative to the arm portion 71 so as to change the amount of protrusion from the arm portion 71. The tip of the push rod 86 is bent upward at a right angle relative to the rod body portion to form a bent portion 86a.

[0081] The pressing piece 87 has a flat support plate portion 87a, left and right side wall portions 87b provided on both sides in the width direction of the support plate portion 87a, and a front wall portion 87c. The front wall portion 87c has a generally U-shaped configuration when viewed in the axial direction of the push rod 86, with a notch 87d (see FIG. 13) that is open on the upper side, corresponding to the shapes of the support plate portion 87a and the left and right side wall portions 87b.

[0082] In the pressing piece 87, the front wall surface of the front wall portion 87c becomes the pressing surface 87e against the seedling block 110. In the pressing piece 87, a space portion 95 is formed between the left and right side wall portions 87b on the support plate portion 87a, with the front side opened by a notch portion 87d. The pressing piece 87 moves integrally with the push rod 86 relative to the arm portion 71.

[0083] The pressing piece 87 is fixed to the push rod 86 by welding or the like, with the bent portion 86a of the push rod 86 passing through the support plate portion 87a. The pressing piece 87 has a side wall portion 87b whose front portion is larger in the up-down direction than its rear portion. The upper edges of the front portions of the left and right side wall portions 87b of the pressing piece 87 are aligned with the claw main body 82 and are positioned inside the claw main body 82, which has a generally L-shaped cross section.

[0084] The pushing member 73 moves back and forth relative to the arm portion 71 between a holding position (see FIG. 16A) which is the rear end position and a pushing position (see FIG. 16B) which is the front end position.

[0085] The holding position of the pusher member 73 is the standby position of the pusher member 73 in the planting claw device 50, and is the position where the planting claw device 50 holds the seedling block 110. When the pusher member 73 is in the holding position, the pressing piece 87 is located in the middle of the claw body 82 in the claw extension direction.

[0086] The extrusion position of the extrusion member 73 is the position of the forward end of the extrusion member 73 relative to the arm portion 71, and is the position in a state where the planting claw device 50 has pushed out (released) the seedling block 110. When the extrusion member 73 is in the extrusion position, the front end of the pressing piece 87 is positioned approximately in the same position as the sharpened portion 82a of the claw main body portion 82 in the claw extension direction.

[0087] The holding plate 74 is a plate-like member having a predetermined curved shape in a side view, allowing for elastic deformation. The holding plate 74 extends in the claw extension direction from the lower side of the arm portion 71, opposite the fixed side of the planting claws 72, with its width direction oriented left and right. The holding plate 74 is provided below the pair of claw main bodies 82 so as to face the claw main bodies 82. The holding plate 74 is formed, for example, from sheet metal having a thickness of about several millimeters.

[0088] The holding plate 74 has a curved shape in side view, and includes, in order from the rear side (toward the arm portion 71) to the front side (toward the tip of the claw main body 82), a base plate portion 74a, an inclined plate portion 74b, and a tip curved portion 74c. The position of the tip of the holding plate 74 in the claw protruding direction is approximately aligned with the position of the tip of the claw main body 82.

[0089] The base plate portion 74a is a portion that extends along the nail extension direction and is parallel to the nail main body portion 82. The base plate portion 74a forms approximately half of the holding plate 74 in the longitudinal direction. The inclined plate portion 74b is a portion that is bent so as to form an obtuse angle with respect to the base plate portion 74a. In a side view, the angle formed by the base plate portion 74a and the inclined plate portion 74b is, for example, approximately 140°. The inclined plate portion 74b gradually narrows the distance between the holding plate 74 and the nail main body portion 82 from the rear side to the front side.

[0090] The tip bent portion 74c is a portion bent at a right angle or an obtuse angle to the inclined plate portion 74b. In a side view, the angle formed between the inclined plate portion 74b and the tip bent portion 74c is, for example, approximately 100°. The tip bent portion 74c gradually widens the distance between the holding plate 74 and the claw main body 82 from the rear side to the front side.

[0091] The holding plate 74 has a convex ridge 74d on the upper side (towards the nail main body 82) formed by the inclined plate portion 74b and the tip bent portion 74c, positioned near the tip of the nail main body 82. The distance between the left and right nail main bodies 82 and the ridge 74d of the holding plate 74 is slightly smaller than the vertical dimension of the seedling block 110. In other words, the vertical dimension of the unit block portion 108 in the seedling mat 100 is slightly larger than the distance between the nail main body 82 and the ridge 74d.

[0092] The holding plate 74 functions as a leaf spring that clamps and holds the seedling block 110 scraped by the claw main body 82 together with the claw main body 82. In other words, the holding plate 74, with its elastic deformation widening the gap between itself and the claw main body 82 from its natural state, clamps the seedling block 110 together with the pair of claw main bodies 82 with a biasing force. The holding plate 74 is supported in a fixed state by the holding plate support part 75.

[0093] The holding plate support part 75 is made of a plate-shaped member with its thickness in the left-right direction, and is attached to the base part 70 of the planting claw device 50 on the left-right side opposite the planting transmission case 51. The holding plate support part 75 is fastened and fixed to the base part 70 with bolts 88.

[0094] The upper edge of the holding plate support portion 75 is positioned near the lower portion of the arm portion 71. A holding plate 74 is fixed to the upper edge of the front portion of the holding plate support portion 75. The holding plate 74 has a fixing surface portion 74e bent at a right angle to the base plate portion 74a on one of the left and right sides (the planting transmission case 51 side) of the base plate portion 74a. The holding plate 74 is fastened to the holding plate support portion 75 at two locations, front and rear, by bolts 89 that pass through the digging claws 76 and the holding plate support portion 75 and nuts 90 that screw into the bolts, with the fixing surface portion 74e aligned along one of the left and right sides of the holding plate support portion 75. Note that the holding plate 74 may also be attached directly to the arm portion 71.

[0095] The digging claws 76 are located below the holding plate 74 and are located on the opposite side of the holding plate support part 75 from the planting transmission case 51 in the left-right direction. The digging claws 76 have a pair of claw bodies 77 and a connecting part 78 provided between the pair of claw bodies 77.

[0096] The claw body 77 is a plate-shaped member with its thickness in the left-right direction, and extends forward in the claw extension direction from the holding plate support portion 75. In a side view, the claw body 77 has a pointed shape that gradually narrows from its base to its tip. In the claw extension direction, the rear end of the claw body 77 is positioned at approximately the same position as the rear end of the holding plate 74, and the tip is positioned forward of the tip of the holding plate 74.

[0097] The excavation claws 76 are provided with the rear portions of the pair of claw bodies 77 aligned along the underside of the base plate portion 74a of the holding plate 74. In the left-right direction, the pair of claw bodies 77 of the excavation claws 76 are positioned slightly inward from the left and right edges of the holding plate 74. The connecting portion 78 is interposed between the rear portions of the pair of claw bodies 77 and functions as a spacer between the left and right claw bodies 77.

[0098] The excavation claws 76 are provided with their rear portions fixed to the holding plate support portion 75. The excavation claws 76 are fastened together with the holding plate 74 to the holding plate support portion 75 by two bolts 89 used to fix the holding plate 74 to the holding plate support portion 75. The bolts 89 pass through the pair of claw bodies 77 and the connecting portion 78 interposed therebetween, and also pass through the holding plate support portion 75 and the fixing surface portion 74e of the holding plate 74, and are screwed into a nut 90.

[0099] When planting seedling blocks 110 with the planting claw device 50, the digging claws 76 dig into the field ahead of the holding plate 74, reducing the contact resistance of the holding plate 74 with the field and thereby protecting the holding plate 74. In addition, by reaching the field ahead of the holding plate 74, the digging claws 76 have the function of preventing the mulch film from becoming entangled with the holding plate 74. The mulch film has a thickness of, for example, 0.004 to 0.02 mm.

[0100] The configuration of the guide rail 48 will be described with reference to Figures 11 to 14. The guide rail 48 is provided on the underside of the seedling carrier 42, and supports the seedling mat 100 by contacting the lower end surface 100b of the seedling mat 100 placed on the seedling carrier 42, thereby determining the position of the seedling mat 100 relative to the trajectory of the planting claws 72.

[0101] The guide rail 48 is made of a plate-like member having a predetermined curved shape, and is configured to have a constant cross-sectional shape that is the same as the shape of both end faces (side view shape) over almost the entire longitudinal direction. The guide rail 48 has, as parts that form the side view shape, a front inclined surface portion 121 that slopes downward to the rear so as to fit along the loading surface of the seedling loading tray 42, and a rear inclined surface portion 122 that, together with the front inclined surface portion 121, forms an approximately "V" shape in side view, and these surfaces form a gutter shape.

[0102] The guide rail 48 has a configuration in which a first rail member 123 forming the front portion in a plan view and a second rail member 124 forming the rear portion in a plan view are connected by a plurality of connecting members 125. The first rail member 123 forms the upper portion of the front inclined surface portion 121, and the second rail member 124 forms the lower portion of the front inclined surface portion 121 and the rear inclined surface portion 122.

[0103] The connecting member 125 is located on the back side of the front inclined surface portion 121 (opposite the side on which the seedling mat 100 is placed) so as to straddle the joint 120 between the end faces of the first rail member 123 and the second rail member 124. The connecting member 125 is a narrow plate-shaped member with its longitudinal direction in the left-right direction, and multiple connecting members 125 are provided in the left-right direction. The connecting member 125 connects the first rail member 123 and the second rail member 124 to each other by receiving fixing screws 126 that pass through the rear edge portion of the first rail member 123 and the front edge portion of the second rail member 124. The guide rail 48 may be formed from an integrated rail member.

[0104] The guide rail 48 has notched openings 49 at multiple locations (four locations) along its length, which accommodate the portions of the seedling mat 100 (unit block portions 108) to be cut by the planting claws 72. As shown in FIG. 13 , the opening 49 has left and right side edges 49a that face each other in the left-right direction and a front edge 49b that extends in the left-right direction. The left and right corners of the opening edge of the opening 49 are formed with chamfered portions 49c that form inclined edges relative to the side edges 49a. The left and right chamfered portions 49c widen the left-right width of the opening end of the opening 49. The opening 49 is notched across the entire front and rear inclined surfaces 121 and 122 in the front-to-rear direction in a plan view.

[0105] As shown in FIG. 13, the left-right width G1 of the intake portion 49, i.e., the distance between the left and right side edges 49a, is approximately the same as the width G2 of the planting claw 72, which has a predetermined width. Specifically, the guide rail 48 has a width G1 of the intake portion 49 that is slightly larger than the width G2 of the planting claw 72. As shown in FIG. 13, the planting claw device 50 is configured so that the left and right sides of the planting claw 72 are positioned inside the left and right side edges 49a of the intake portion 49 in the left-right direction by a predetermined gap G3. The size of the gap G3 is, for example, several millimeters (e.g., 3 mm). The planting claw device 50 is configured to perform a planting operation while maintaining a predetermined position in the left-right direction, and the size of the gap G3 is maintained during the planting operation of the planting claw device 50.

[0106] The guide rail 48 has a contact support surface portion 130 that comes into contact with the lower end surface portion 100b of the seedling mat 100, and a groove forming portion 133 that forms a concave groove 131 in the contact support surface portion 130 and leaves a space 132 between it and the lower end surface portion 100b of the seedling mat 100. The contact support surface portion 130 has a shape that follows the groove forming surface 103a that forms the front side groove portion 103 of the seedling mat 100. The contact support surface portion 130 has an inclined support surface portion 134 as a portion that follows the groove forming surface 103a.

[0107] The contact support surface portion 130 is a rear portion of the rear inclined surface portion 122 in the width direction (the direction along the front-rear direction in a plan view) of the guide rail 48. The contact support surface portion 130 is provided as an upper rear portion of the rear inclined surface portion 122, which forms a surface portion that is inclined upward toward the rear.

[0108] In the contact support surface portion 130, the inclined support surface portion 134 is the portion that comes into contact with the groove forming surface 103a of the lower end surface portion 100b of the seedling mat 100 in the set state placed on the seedling carrier 42. The inclined support surface portion 134 is inclined so as to be parallel or approximately parallel to the groove forming surface 103a of the lower end surface portion 100b of the seedling mat 100 in the set state, depending on the shape of the front side groove portion 103 of the seedling mat 100, etc.

[0109] The contact support surface portion 130 has, on the rear side of the inclined support surface portion 134, an edge surface portion 135 that forms the rear edge end portion of the guide rail 48. The contact support surface portion 130 is formed as a curved surface portion that forms an obtuse angle in side view by the inclined support surface portion 134 and the edge surface portion 135.

[0110] In the example shown in Figure 14, the inclined support surface portion 134 is inclined so that the angle θ1 between the vertical direction and the inclination direction of the loading surface of the seedling loading tray 42 in side view (see arrow H1, hereinafter referred to as the "loading surface inclination direction") is approximately 30°. However, the inclination angle of the inclined support surface portion 134 is not limited and can be determined appropriately depending on the shape of the surface side groove portion 103 of the seedling mat 100, etc.

[0111] In the following, the direction perpendicular to the inclination direction of the placing surface in a side view is referred to as the placing surface perpendicular direction (see arrow H2 in Figure 14). The placing surface inclination direction corresponds to the vertical feed direction of the seedling mat 100. Furthermore, the vertical direction of the seedling mat 100 in the set state corresponds to the placing surface inclination direction, and the thickness direction of the seedling mat 100 in the set state corresponds to the placing surface perpendicular direction.

[0112] The groove forming portion 133 is formed by a front lower portion of the rear inclined surface portion 122 and a rear lower portion of the front inclined surface portion 121. The groove forming portion 133 has, as portions formed by the rear inclined surface portion 122, a rear groove side surface portion 136 which is a surface portion along the inclination direction of the placing surface in a side view, and a groove bottom surface portion 137 which is a surface portion along the direction perpendicular to the placing surface in a side view.

[0113] Furthermore, groove forming portion 133 has a front groove side surface portion 138 that is formed by front inclined surface portion 121 and extends along the inclination direction of the mounting surface in a side view. Front groove side surface portion 138 is a portion on the lower end side of front inclined surface portion 121, and is a portion that faces rear groove side surface portion 136 in the direction orthogonal to the mounting surface. Rear groove side surface portion 136 and front groove side surface portion 138 are each portions that are bent at right angles to groove bottom surface portion 137 on both sides of groove bottom surface portion 137 in the direction orthogonal to the mounting surface, with corners being curved surface portions (R-shaped portions).

[0114] In this way, the groove forming portion 133 forms a substantially U-shaped groove portion that is open on the side of the seedling mat 100 in the set state and conforms to a substantially rectangular shape in side view, with the rear groove side portion 136, front groove side portion 138, and groove bottom portion 137. The lower side of the inclined support surface portion 134 is connected to the upper side of the rear groove side portion 136. The rear groove side portion 136 and the inclined support surface portion 134 form a curved surface portion with an obtuse angle in side view.

[0115] The upper side of the front groove side surface portion 138 extends along the inclination direction of the placing surface in a side view as an upper portion of the front inclined surface portion 121. A support edge portion 139 is provided on the upper edge portion of the front inclined surface portion 121, and is bent forward to form a right angle with the corner portion as a curved surface portion.

[0116] As shown in FIG. 14, the seedling mat 100 supported by the guide rail 48 is supported with the groove forming surface 103a at the end surface 100b in contact with the inner surface 134a of the inclined support surface portion 134, and with the portion below the groove forming surface 103a (the lower surface 104b side) facing into the recessed groove 131. In other words, the seedling mat 100 is supported by the guide rail 48 with the groove forming surface 103a in contact with the inclined support surface portion 134 at the end surface 100b, and the intermediate surface 109a and the groove forming surface 107a face the groove bottom surface portion 137 across the space 132. The inner surface 134a of the inclined support surface portion 134 serves as a sliding surface, or guide surface, for the seedling mat 100 being fed laterally.

[0117] In the guide rail 48, the edge surface portion 135 forming the rear edge is, in a side view, the portion that extends upward above the upper surface 104a of the seedling mat 100 in the direction perpendicular to the placing surface. Also, in the guide rail 48, the surface 121a of the front inclined surface portion 121 is the surface that comes into contact with the lower surface 104b of the lower end row block portion 104. The front inclined surface portion 121 has a length (width) that includes the entire length of at least one row of row block portions 104 in the inclination direction of the placing surface.

[0118] As described above, the guide rail 48 has, as parts that form a curved shape when viewed from the side, a front inclined surface portion 121 whose lower part is a front groove side surface portion 138, a rear groove side surface portion 136 and a groove bottom surface portion 137 that form a concave groove 131 together with the front groove side surface portion 138, and an inclined support surface portion 134 and an edge surface portion 135 that form the contact support surface portion 130.

[0119] In the guide rail 48, cutting assistant parts 140 are provided at the open ends of the recessed grooves 131 facing the intake portions 49, where the recesses of the recessed grooves 131 are eliminated or reduced. The cutting assistant parts 140 are provided on both the left and right sides of each intake portion 49, and the cutting assistant parts 140 on both the left and right sides of each intake portion 49 are configured symmetrically in the left-right direction. Note that the cutting assistant parts 140 are not shown in Figure 14.

[0120] The cutting auxiliary portions 140 are formed by partially raising the bottom of the recessed groove 131 by the depth of the recessed groove 131 on both the left and right sides of the intake portion 49. The cutting auxiliary portions 140 are provided by attaching a cutting auxiliary member 150 to the open end of the recessed groove 131 in the guide rail 48, which faces the intake portion 49. The cutting auxiliary member 150 is a metal member in the shape of a substantially rectangular plate or block, and is fixed to the guide rail 48 while fitted into the recessed groove 131.

[0121] 11 and 13, the cutting auxiliary member 150 has a rectangular outer shape in a plan view, and is oriented with its longitudinal direction aligned with the extension direction of the recessed groove 131. The cutting auxiliary member 150 has a first end face 151 which is an end face on one side in the longitudinal direction, and a second end face 152 which is an end face on the other side in the longitudinal direction. The cutting auxiliary member 150 has a width dimension which is approximately the same as the width dimension of the recessed groove 131, and is arranged in a manner such that it fits between the rear groove side surface portion 136 and the front groove side surface portion 138 of the recessed groove 131. The cutting auxiliary member 150 also has a horizontal upper surface 156.

[0122] The cutting assist member 150 is fixed to the guide rail 48 by one screw 161. The screw 161 passes through the groove bottom surface 137 of the recessed groove 131 from below the guide rail 48 and is threaded into a screw hole 158 formed in the cutting assist member 150. The screw hole 158 is formed to pass through the cutting assist member 150 in the thickness direction. The groove bottom surface 137 is formed with a hole 137b for passing the screw 161 through (see FIG. 14).

[0123] The cutting auxiliary member 150 is provided so that the first end surface 151 faces the intake portion 49 side of the guide rail 48. The cutting auxiliary member 150 is provided so that the first end surface 151 is flush with the end surface that forms the side edge portion 49a of the intake portion 49.

[0124] In the configuration in which the cutting assist member 150 is attached to the recessed groove 131 of the guide rail 48 as described above, the upper surface 156 forms a cutting assist surface that is raised from the bottom surface 137a of the recessed groove 131 by the depth of the groove. In other words, the cutting assist portion 140 is a portion of the recessed groove 131 where there is no recess, and in the cutting assist portion 140, the cutting assist member 150 forms the upper surface 156 as a surface that is raised from the bottom surface 137a of the recessed groove 131 by the thickness of the cutting assist member 150. The bottom surface 137a is the inner surface of the groove bottom portion 137.

[0125] In this embodiment, the cutting auxiliary member 150 has a thickness substantially equal to the depth of the recessed groove 131, and at the portion of the recessed groove 131 where the cutting auxiliary member 150 is disposed, substantially the entire depth of the recessed groove 131 is filled with the cutting auxiliary member 150. In other words, at the portion where the cutting auxiliary member 150 is disposed, the open end of the recessed groove 131 is closed by the cutting auxiliary member 150, and there is no depression in the recessed groove 131. Note that the cutting auxiliary portion 140 may not be configured by attaching the cutting auxiliary member 150 to the guide rail 48, but may be provided as a shaped part of the guide rail 48 itself.

[0126] The operation of the planting claw device 50 having the above-described configuration will be described with reference to Figures 15 and 16. For ease of explanation, the furrowing arm 200 and its support mechanism, which will be described later, are omitted from Figures 15 and 16. As shown in Figures 15A to 15C and 16A and 16B, the planting claw device 50 rotates continuously as the rotary case 52 (see Figure 6) is rotated by the drive shaft 52a, so as to repeatedly remove (scrape) seedling blocks 110 from the seedling mat 100 supported on the guide rails 48, transport the seedling blocks 110 while temporarily holding them, and plant the seedling blocks 110.

[0127] Figure 15A shows the state just before the planting claw device 50 scrapes off the seedling mat 100. As shown in Figure 15A, the planting claw device 50 brings the claw body 82 from the upper rear side toward the guide rail 48 that supports the seedling mat 100 from below. The planting claw device 50 targets one unit block 108 of the row block portion 104 at the bottom of the seedling mat 100 supported by the guide rail 48 as the target for scraping, and brings the claw body 82 closer to that unit block 108. The unit block 108 to be scraped is located above the intake portion 49 of the guide rail 48.

[0128] As shown in FIG. 15B, the planting claw device 50 cuts the tip of the claw main body 82 into the seedling mat 100 from the surface groove portion 103 on the upper side of the unit block portion 108 to be scraped.

[0129] Then, as the planting claw device 50 moves downward and forward, as shown in FIG. 15C, the planting claw 72 scrapes off the unit block portion 108, which is then held by the planting claw device 50 as a seedling block 110. Here, the unit block portion 108 is scraped off while being sandwiched between the pair of claw main bodies 82 and the holding plate 74. When scraping off the unit block portion 108, a guide action is provided by the tip bent portion 74c, which widens the gap between the tips of the claw main body 82 and the holding plate 74. Furthermore, the unit block portion 108 to be scraped off is guided by the groove shape of the surface side groove portion 103, which receives the tip of the claw main body 82.

[0130] When scraping the seedling mat 100, the planting claw device 50 acts on the seedling mat 100 while tracing a predetermined trajectory E1 (see Figure 12) of the movement trajectory of the tip of the claw main body 82 relative to the guide rail 48 in a side view. The trajectory E1 has a curved shape with the upper side convex near the guide rail 48, forming a loop shape overall. In a side view, the tip of the claw main body 82 passes near the boundary between adjacent row block portions 104 (virtual line B1 in Figure 10).

[0131] Furthermore, when scraping the seedling mat 100, the cutting auxiliary part 140 is provided at the open end of the guide rail 48 relative to the intake part 49, thereby achieving good cutting (cutting) performance. That is, the cutting auxiliary part 140 fills the space 132 of the recessed groove 131, which serves as an escape space for the seedling mat 100, on the underside of the seedling mat 100 that is acted upon from above by the planting claws 72. The cutting auxiliary part 140 also supports the seedling mat 100 from below, even at the formation part of the recessed groove 131, preventing escape of the seedling mat 100 and achieving good shearing action. This allows for stable scraping.

[0132] As shown in Figure 15C, the seedling block 110 scraped off by the planting claws 72 is sandwiched and held between the pair of claw bodies 82 and the holding plate 74. In the holding plate 74 that holds the seedling block 110 together with the pair of claw bodies 82, the ridge portion 74d is the main contact portion with the seedling block 110. For example, when the seedling block 110 is being held, the elastic deformation of the holding plate 74 widens the gap between the pair of claw bodies 82 and the holding plate 74 compared to the state before the seedling block 110 was held.

[0133] The pressing piece 87 is located behind the seedling block 110 when it is held by the planting claw device 50. In addition, in the planting claw device 50, the space 85 between the left and right claw bodies 82 and the space 95 of the pressing piece 87 (see Figure 11) serve as spaces for positioning the seedlings 106 of the seedling block 110 when it is held, preventing the seedlings 106 from interfering with the planting claw device 50.

[0134] As shown in FIG. 16A, the planting claw device 50, while holding the seedling block 110, moves downward with the tips of the planting claws 72 facing downward. Then, as shown in FIG. 16B, the planting claw device 50 pushes out (releases) the seedling block 110 using the pusher member 73 at a predetermined timing when the tips of the planting claws 72 are positioned within the field below the field surface, i.e., the field level 91. The planting claw device 50 moves the pusher member 73 forward relative to the arm 71, causing the pusher member 73 to push out the seedling block 110 in the claw extension direction (see arrow F1). The seedling block 110 is released with the force of the push from the pusher member 73 and planted in the field at a predetermined planting depth.

[0135] When the pushing member 73 pushes out the seedling blocks 110, the pushing member 73 presses the seedling blocks 110 with the pressing surface 87e of the pressing piece 87 as the contact surface with the seedling blocks 110. The contact surface of the pressing surface 87e with the seedling blocks 110 corresponds to the upper surface 104a of the seedling mat 100. The pushing member 73 also moves forward with a biasing force against the arm portion 71, pushing out the seedling blocks 110 in a pop-out manner. When the seedling blocks 110 are planted in the field, the rear side is covered by the holding plate 74, protecting them from collision with the field.

[0136] Furthermore, when the planting claw device 50 acts on the field surface 91, the digging claws 76 dig into the field surface 91 before the holding plate 74. This reduces the contact resistance of the holding plate 74 with the field surface 91, protecting the holding plate 74 and preventing the mulch film from becoming entangled with the holding plate 74.

[0137] After planting the seedling blocks 110 in the field, the planting claw device 50 gradually returns the pusher member 73, which is in the push position, to the holding position while moving upward relative to the field surface 91. The planting claw device 50 then returns to a position where the planting claws 72 are positioned above and behind the guide rail 48, and proceeds to scrape the next unit block 108 and plant the seedlings. In this way, the planting claw device 50 rotates in a loop-shaped trajectory E1 about the tip of the claw body 82, scraping one unit block 108 and planting one seedling block 110 in one cycle, planting seedlings consecutively in a line with a predetermined spacing between plants as the machine body moves forward.

[0138] In the seedling mat 100, the row block portion 104 at the bottom, i.e., the row block portion 104 located on the guide rail 48, is the target to be scraped off during one stroke of the seedling mat 100 as it is fed laterally to either the left or the right. As the seedling mat 100 is fed laterally to either the left or the right, the planting claw device 50 performs continuous planting operations, and at a predetermined timing when all of the unit block portions 108 of the row block portion 104 located at the bottom have been scraped off, the seedling mat 100 is fed vertically by one row by the delivery belt 47.

[0139] After the seedling mat 100 has been fed vertically, the unit block portions 108 of the newly positioned lower row block portion 104 are continuously scraped off one by one while the seedling mat 100 is fed laterally to the left or right. In this way, the seedling mat 100 is intermittently fed vertically while moving back and forth in the left and right directions by the horizontal feed, and is scraped off sequentially from the lower row block portion 104 by the planting claw device 50.

[0140] As described above, the seedling transplanter 1 is configured to feed the seedling mat 100 placed on the seedling carrier 42 in a horizontal feed direction along the left-right direction of the machine body, and to intermittently feed the seedling mat 100 in a vertical feed direction along the front-to-back direction of the machine body in a plan view, while cutting off portions of the seedling mat 100 with the planting claws 72 and continuously planting seedlings 106 in the field.

[0141] As shown in Figures 6, 17 to 21, the seedling transplanter 1 having the above configuration is equipped with a furrow making arm 200 in the seedling transplanting device 3 as a component for performing pre-treatment of the field, such as forming furrows in the field and cutting mulch film, before planting seedlings with the planting claws 72. A furrow making arm 200 is provided corresponding to each of the four planting claw devices 50, and the seedling transplanting device 3 has four furrow making arms 200. The furrow making arms 200 and the link mechanisms 300 and cam mechanisms 400 (described below) provided for the furrow making arms 200 are configured symmetrically with the planting transmission case 51 as the center, in a configuration in which the planting claw devices 50 are arranged on both the left and right sides of the planting transmission case 51.

[0142] The furrowing arm 200 is attached to the planting claw device 50. The furrowing arm 200 is configured longitudinally, and is provided so that its longitudinal direction is aligned with the claw extension direction. The furrowing arm 200 is provided near the planting claw 72 relative to the planting claw device 50.

[0143] The furrow making arm 200 is provided in a state in which it is supported movably relative to the planting claw device 50 by a link mechanism 300. As a result, the furrow making arm 200 is provided so as to move relative to the planting claw 72.

[0144] The furrowing arm 200 is configured to have a generally U-shape with the rear side open, and is provided to surround the planting claw device 50 from the left and right sides and the front. The furrowing arm 200 has an arm main body 201, an arm tip 202, and an auxiliary arm 203 as parts that form the generally U-shaped outer shape. These parts that make up the furrowing arm 200 are provided as plate-like parts having predetermined shapes.

[0145] The groove making arm 200 has, as its constituent members, a support plate 204 and a cutter member 205. The support plate 204 and the cutter member 205 are connected and fixed to each other to form the groove making arm 200 as a single unit.

[0146] The support plate 204 is a substantially rectangular plate-like member whose longitudinal direction is the extension direction of the groove making arm 200 when viewed from the side, and forms a support base for the groove making arm 200. In detail, the support plate 204 has a front portion that is narrower than the rear portion, and has a shape (plate surface shape) when viewed from the side that tapers gently from the rear side to the front side.

[0147] The cutter member 205 is a bent plate-like member that is substantially U-shaped in plan view, and forms the main body of the groove making arm 200. The cutter member 205 has an outer side surface portion 205a, a front side surface portion 205b, and an inner side surface portion 205c as surfaces that form the substantially U-shape (see FIG. 21).

[0148] The arm main body 201 is positioned offset to one side in the left-right direction relative to the planting claw 72. With regard to the positioning of the arm main body 201, the one side in the left-right direction relative to the planting claw 72 is the opposite side to the planting transmission case 51 in the left-right direction. In describing the furrow making arm 200, the planting transmission case 51 side (upper side in Figure 19) is referred to as the inside in the left-right direction, and the side opposite the planting transmission case 51 side (lower side in Figure 19) is referred to as the outside. The arm main body 201 is a plate-shaped part with its thickness direction in the left-right direction, and is formed by a support plate 204 and an outer surface portion 205a of a cutter member 205.

[0149] The cutter member 205 is fixed to the support plate 204 with the rear end of the outer surface portion 205a overlapping the front end of the support plate 204 from the outside. The rear end of the outer surface portion 205a has approximately the same width as the front end of the support plate 204, and forms a continuous shape with the support plate 204 at the midpoint between the front and rear of the arm main body 201.

[0150] Furthermore, the outer surface portion 205a of the cutter member 205 forming the front portion of the arm main body portion 201 has a generally mountain-shaped bent shape forming an apex 205d at the center between the front and rear in a side view (see FIG. 18). In a side view, the outer surface portion 205a has a shape in which the front side is narrower than the base side, which is the connection side to the support plate 204.

[0151] The arm tip 202 is provided on the tip side of the arm main body 201. The arm tip 202 is located forward of the tip of the digging claw 76 of the planting claw device 50. The arm tip 202 is a plate-shaped portion bent so as to form a right angle toward the left and right inner side with respect to the outer surface portion 205a of the cutter member 205, and is formed by the front side surface portion 205b of the cutter member 205. In this way, the arm tip 202 is connected at its left and right outer sides, which are one end side in the left and right direction, to the tip of the arm main body 201, and is a portion that is connected at its left and right outer sides to the tip of the arm main body 201.

[0152] The arm tip 202 has an inclined surface that slopes downward toward the front with respect to a direction perpendicular to the claw extension direction in a side view. The arm tip 202 is a plate-like portion that is linear in a side cross-sectional view (see FIG. 22). FIG. 22 is a left side cross-sectional view of the groove making arm 200 at the center position in the left and right directions. As shown in FIG. 22, the arm tip 202 has a linear shape with a predetermined direction (see arrow Y1) as the extension direction in a side cross-sectional view.

[0153] The lower edge of the arm tip 202 forms a tip protrusion 202a that protrudes downward relative to the tips of the arm main body 201 and the auxiliary arm 203. The lower edge of the arm tip 202 has a downwardly convex mountain shape with a pair of oblique sides 202b forming an apex 202c. The apex 202c is an obtuse-angled corner formed by the pair of oblique sides 202b.

[0154] The auxiliary arm portion 203 is located on the other side of the planting claw 72 in the left-right direction, that is, offset toward the planting transmission case 51 (inside). In other words, the auxiliary arm portion 203 is located on the opposite side of the arm main body portion 201 in the left-right direction with respect to the planting claw 72. The auxiliary arm portion 203 is a plate-shaped portion bent at a right angle toward the rear side relative to the front side surface portion 205b of the cutter member 205, with the left-right direction being the plate thickness direction, and is formed by the inner side surface portion 205c of the cutter member 205. In this way, the auxiliary arm portion 203 has one end, the front end, connected to the other end, the left-right inner side, of the arm tip portion 202, and the front end is connected to the left-right inner side of the arm tip portion.

[0155] The auxiliary arm portion 203 is a relatively narrow portion compared to the outer surface portion 205a of the cutter member 205, has a substantially constant width, and in a side view, is inclined in substantially the same direction as the front portion of the outer surface portion 205a and extends substantially linearly. The auxiliary arm portion 203 has a sharpened tip portion 203a that forms an acute angle on the upper side of the rear end. In the state shown in Figure 19, the auxiliary arm portion 203 is positioned such that the sharpened tip portion 203a is located near the rear portion on the inner left and right sides of the claw body portion 82 on the inner left and right sides of the planting claw 72 (upper side in Figure 19).

[0156] The cutter member 205 is fixed to the support plate 204 by two bolts 206 serving as fixing members. The two bolts 206 are located on both sides in the width direction of the arm main body 201 at the overlapping portion between the outer surface portion 205a of the cutter member 205 and the support plate 204. The bolts 206 pass through holes 205e formed in the rear end portion of the outer surface portion 205a and are screwed into threaded holes formed in the front end portion of the support plate 204.

[0157] The hole 205e through which the bolt 206 passes is an elongated hole with its longitudinal direction aligned with the direction in which the cutter member 205 extends from the support plate 204. This makes it possible to adjust the fixed position of the cutter member 205 in the extension direction relative to the support plate 204. Adjusting the fixed position of the cutter member 205 relative to the support plate 204 involves adjusting the position of the arm tip 202 in the direction toward or away from the tip of the planting claw 72.

[0158] The link mechanism 300 will now be described. The link mechanism 300 supports the furrowing arm 200 so that it can move back and forth in the front-to-rear direction relative to the holding plate support part 75 that constitutes the planting claw device 50. The holding plate support part 75 is fixed at multiple locations with bolts 88 to the case body 70a that constitutes the base 70 of the planting claw device 50. The holding plate support part 75 has a substantially rectangular or substantially trapezoidal shape in side view, and its lower edge forms a downward protrusion 75a that protrudes downward from the case body 70a that constitutes the base 70 (see Figure 18). The holding plate support part 75 is located below the arm part 71.

[0159] Link mechanism 300 includes two link arms: front arm 301, which serves as a first link arm located on the front side, and rear arm 302, which serves as a second link arm located on the rear side. Front arm 301 and rear arm 302 are linear plate-like members whose thickness direction is in the left-right direction.

[0160] The front arm 301 and the rear arm 302 have one longitudinal end rotatably supported by the holding plate support part 75 on the planting claw device 50 side, and the other end rotatably supported on the furrowing arm 200 side. Both arms 301, 302 have approximately the same length and are arranged to be approximately parallel to each other. Both arms 301, 302 are arranged on the outer lateral sides of the holding plate support part 75 and on the inner lateral sides of the support plate 204 that constitutes the furrowing arm 200. In other words, both arms 301, 302 are located between the holding plate support part 75 and the support plate 204 in the left-right direction.

[0161] The lower ends of the front arm 301 and the rear arm 302 are rotatably supported by front bosses 303 and rear bosses 304 provided in front of and behind downward protrusion 75a of retaining plate support part 75 via shaft-shaped support members 305 or the like and bearing members (not shown). Front boss 303 and rear boss 304 are cylindrically protruding portions on both the left and right sides of the plate-shaped main body of retaining plate support part 75. The support portion of the lower end of front arm 301 relative to front boss 303 is front fixed support portion 311, and the support portion of the lower end of rear arm 302 relative to rear boss 304 is rear fixed support portion 312 (see FIG. 18 ).

[0162] The upper end of the forearm 301 is rotatably supported by a boss 306 provided in the approximate center of the support plate 204 via a bearing member (not shown) using a support bolt 307 or the like which is a support member. The boss 306 is a cylindrical portion that protrudes on both the left and right sides of the plate-like main body of the support plate 204, and is provided at a position behind the portion of the support plate 204 that receives the fixed outer surface portion 205a of the cutter member 205. The support portion of the upper end of the forearm 301 that supports the boss 306 is called a front moving support portion 313 (see FIG. 18).

[0163] The upper end of the rear arm 302 is rotatably supported by a connecting plate 310 attached to the support plate 204. In other words, the upper end of the rear arm 302 is pivotally supported by the support plate 204 via the connecting plate 310.

[0164] The connecting plate 310 is a plate-like member having a substantially rounded rectangular or elliptical shape, and is located on the left and right inside of the rear end of the support plate 204, with its longitudinal direction oriented in the width direction of the support plate 204. The connecting plate 310 is located so that its entirety is within the outer shape of the support plate 204 in a side view. The connecting plate 310 has a boss portion 321 in approximately the center.

[0165] The upper end of the rear arm 302 is rotatably supported by a boss 321 of the connecting plate 310 via a bearing member (not shown) using a support bolt 322 or the like which serves as a support member. The boss 321 is a cylindrical portion that protrudes on both the left and right sides of the plate-like main body of the connecting plate 310. A relief hole 204a is formed through the support plate 204 to avoid interference with the boss 321 of the connecting plate 310. The portion where the upper end of the rear arm 302 is supported by the boss 321 is called a rear moving support portion 314 (see FIG. 18).

[0166] The connecting plate 310 is fixed to the support plate 204 at two locations on both ends in the longitudinal direction by bolts 323 serving as fixing members. The bolts 323 pass through holes 204b formed in the rear part of the support plate 204 and are threaded into threaded holes formed in the connecting plate 310. The fixing portions provided by the bolts 323 are located on both sides of the boss portion 321 in the longitudinal direction of the connecting plate 310.

[0167] The hole 204b through which the bolt 323 passes is an elongated hole with its longitudinal direction aligned with the longitudinal direction of the groove making arm 200 in a side view. This makes it possible to adjust the fixed position of the connecting plate 310 relative to the support plate 204. Adjusting the fixed position of the connecting plate 310 relative to the support plate 204 involves adjusting the position of the rear moving pivot support part 314 on the support plate 204.

[0168] That is, by adjusting the fixed position of the connecting plate 310 relative to the support plate 204, the inter-axial distance L1 (see FIG. 20) between the rotation axis Q3 of the front moving pivotal support portion 313 and the rotation axis Q4 of the rear moving pivotal support portion 314 is adjusted. The relief hole 204a for the boss portion 321 has a length that prevents the boss portion 321 from interfering with the support plate 204 within the range of position adjustment of the connecting plate 310 by the hole portion 204b in the support plate 204, and is formed as an elongated hole aligned longitudinally with the hole portion 204b.

[0169] As described above, the link mechanism 300 including the two arms, the front arm 301 and the rear arm 302, is a four-joint link with the axes of the four pivotal supports, the front fixed pivotal support 311, the rear fixed pivotal support 312, the front movable pivotal support 313, and the rear movable pivotal support 314, as nodes, and movably connects and supports the furrowing arm 200 relative to the holding plate support 75. The link mechanism 300 rotates the front arm 301 and the rear arm 302 relative to the front fixed pivotal support 311 and the rear fixed pivotal support 312, which are fixed in position relative to the planting claw device 50 side, thereby moving the front movable pivotal support 313 and the rear movable pivotal support 314 provided on the furrowing arm 200 side.

[0170] The front arm 301 and the rear arm 302 rotate about the pivotal support of the front fixed pivotal support portion 311 and the rear fixed pivotal support portion 312, respectively, to reciprocate the furrow making arm 200 back and forth relative to the planting claw device 50. During the reciprocating movement of the furrow making arm 200, the distance between the axes of the front fixed pivotal support portion 311 and the rear fixed pivotal support portion 312 (the distance between the pivotal axis Q1 of the front fixed pivotal support portion 311 and the pivotal axis Q2 of the rear fixed pivotal support portion 312) and the distance between the axes of the front moving pivotal support portion 313 and the rear moving pivotal support portion 314 (the distance between the pivotal axis Q3 and the pivotal axis Q4) are constant.

[0171] As described above, the furrow making arm 200, which is movably supported by the link mechanism 300, has a standby position (see Figure 20) and a furrow making position (see Figure 18) as positions and postures during its reciprocating movement, that is, positions and postures relative to the planting claws 72. The standby position of the furrow making arm 200 is the position and posture at the timing when the planting claws 72 cut the seedling mat 100. The furrow making position of the furrow making arm 200 is the position and posture when it has moved forward relative to the planting claws 72 when planting seedlings (seedling blocks 110) in the field. Note that Figure 19 shows the furrow making arm 200 in the furrow making position.

[0172] The link mechanism 300 biases the groove making arm 200 toward the groove making posture by means of a groove making arm return spring 330. The groove making arm return spring 330 is a so-called torsion spring, and has extensions 330a, 330b on both ends of a coil-shaped portion (see Figure 18). The groove making arm return spring 330 is provided in the front fixed pivot support portion 311 with the coil-shaped portion fitted onto the front boss portion 303.

[0173] Grooving arm return spring 330 has one extension portion 330a extending rearward to abut against rear boss portion 304 from above, and the other extension portion 330b engaged with front arm 301. The other extension portion 330b is engaged with front arm 301 by bending its tip end to abut against the rear side of the middle portion of front arm 301.

[0174] The furrowing arm return spring 330 biases the front arm 301 in a direction in which the furrowing arm 200 moves forward relative to the holding plate support portion 75, that is, in a counterclockwise rotation direction when viewed from the left side (see arrow J1 in Figure 18). As a result, the furrowing arm 200 is biased toward the furrowing position relative to the planting claw device 50.

[0175] The furrowing arm 200 moves back and forth relative to the planting claw device 50 in conjunction with the relative rotation of the planting claw device 50 relative to the rotary case 52, which performs a predetermined planting operation in accordance with the rotation of the rotary case 52. The furrowing arm 200 performs periodic reciprocating motion, with one rotation being one cycle, in response to the relative rotation of the planting claw device 50 relative to the rotary case 52. Figure 19 shows the case-side rotation axis O1, which is the rotation center of the rotary case 52 relative to the planting transmission case 51 and coincides with the axis of the drive shaft 52a (see Figure 3), and the claw-side rotation axis O2, which is the rotation center of the planting claw device 50 relative to the rotary case 52 and coincides with the axis of the rotation shaft 50a (see Figure 3).

[0176] The furrowing arm 200 moves back and forth in conjunction with the relative rotation of the planting claw device 50 with respect to the rotary case 52 about the claw-side rotation axis O2 (hereinafter referred to as "relative rotation of the planting claw device 50") via the cam mechanism 400. In other words, the cam mechanism 400 converts the relative rotation of the planting claw device 50 into the reciprocating pivotal movement of the front arm 301 and the rear arm 302 of the link mechanism 300, thereby causing the furrowing arm 200 to move back and forth.

[0177] The furrow making arm 200 changes its position and posture relative to the planting claw 72 in conjunction with the movement of the planting claw 72 by a cam mechanism 400 including a cam plate 410 as a cam. The cam plate 410 is attached to a rotary case 52 that rotatably supports the planting claw device 50 including the planting claw 72, and changes the relative position of the furrow making arm 200 to the planting claw 72 as the planting claw device 50 rotates.

[0178] The cam plate 410 is a substantially disk-shaped member, and is fixed to the rotary case 52 by a fixing member (not shown). In other words, the cam plate 410 is a part that rotates integrally with the rotary case 52. The cam plate 410 is interposed between the rotary case 52 and the case body 70a of the planting claw device 50, with the plate thickness direction oriented in the left-right direction (see FIG. 19).

[0179] As shown in Figure 23, the cam plate 410 has an outer shape (plate surface shape) in which a portion of the outer periphery of the circular shape has been cut away in a substantially linear manner. When viewed in the axial direction of the central axis P1 along the left-right direction, the outer peripheral surface of the cam plate 410 forms a cam surface 411 that acts on the guide roller 402, which will be described later. The position of the central axis P1 of the cam plate 410 coincides with the claw-side rotation axis O2 of the planting claw device 50 (see Figure 19). Note that Figure 23 shows an example of the shape of the cam surface 411.

[0180] 23, cam surface 411 has a first arc-shaped cam surface portion 412 and a second arc-shaped cam surface portion 413 provided on the opposite side of first arc-shaped cam surface portion 412 with respect to the position of central axis P1. Both first arc-shaped cam surface portion 412 and second arc-shaped cam surface portion 413 have an arc shape centered on the position of central axis P1 of cam plate 410. Cam plate 410 has a shape that is line-symmetrical with respect to a predetermined straight line P2 that passes through central axis P1.

[0181] In this embodiment, the radius of the circumferential shape of second arc-shaped cam surface portion 413 is approximately one-third the radius of the circumferential shape of first arc-shaped cam surface portion 412. First arc-shaped cam surface portion 412 is formed over an angular range of approximately 260° in the circumferential direction about central axis P1. Second arc-shaped cam surface portion 413 is formed over an angular range of approximately 45° in the circumferential direction about central axis P1.

[0182] On cam surface 411, linear cam surface 414, which is a linear cam surface portion, is formed between the ends of first arc cam surface portion 412 and second arc cam surface portion 413. Linear cam surface 414 is located on both sides of line P2. Linear cam surface 414 smoothly connects the ends of first arc cam surface portion 412 and second arc cam surface portion 413.

[0183] In addition, the cam mechanism 400 has a configuration provided on the planting claw device 50 side, which includes a guide roller 402 that acts on the cam plate 410 and a roller support arm 403 that supports the guide roller 402 relative to the retaining plate support portion 75.

[0184] The roller support arm 403 is provided on the left and right inner side of the holding plate support part 75. The roller support arm 403 is an arm-shaped member, and one end side of the roller support arm 403 is rotatably supported by the front boss part 303 that supports the front arm 301 via a bearing member (not shown) by a bolt-shaped pivot member 404 or the like (see FIG. 19).

[0185] The roller support arm 403 is provided so that its rotation axis coincides with that of the front arm 301 and so as to maintain a positional relationship with the front arm 301 in the rotation direction. In other words, the roller support arm 403 and the front arm 301 are supported coaxially at the front fixed pivot support portion 311 by the front boss portion 303, and are provided in a fixed state to each other so as to rotate integrally around the rotation axis Q1.

[0186] Guide roller 402 is a cylindrical rotating body that is located to the right of the tip of roller support arm 403 and is supported by a predetermined pivot member on roller support arm 403 so as to be rotatable about its rotation axis in the left-right direction. Guide roller 402 is supported by roller support arm 403 in a position where it contacts cam plate 410 from below.

[0187] 18, the roller support arm 403 extends rearward relative to the front arm 301, which extends upward from the front boss portion 303. The front arm 301 and the roller support arm 403 are disposed so as to form an angle of approximately 80 to 90° when viewed in the axial direction of the rotation axis Q1. The angle formed by the front arm 301 and the roller support arm 403 is an angle β1 formed by a line connecting the rotation axis Q1 of the front fixed journal portion 311 and the rotation axis Q3 of the front movable journal portion 313, and a line connecting the rotation axis Q1 and the rotation axis Q5, which is the rotation center of the guide roller 402 (see FIG. 20).

[0188] The guide roller 402 is biased in a direction to be pressed against the cam plate 410 via the roller support arm 403 by the biasing force of the groove forming arm return spring 330 against the front arm 301. As a result, the guide roller 402 moves along the cam surface 411 as the planting claw device 50 rotates relative to the guide roller 402.

[0189] According to the above configuration, the contact position of the guide roller 402 with the cam plate 410 moves toward or away from the central axis P1 of the cam plate 410 in response to changes in the distance from the central axis P1 of the cam plate 410 due to the cam surface 411 caused by the relative rotation of the planting claw device 50. This movement of the guide roller 402 results in the integral rotation of the roller support arm 403 and the forearm 301 about the rotation axis Q1. The rotation of the forearm 301 operates the link mechanism 300, causing the furrow making arm 200 to perform a predetermined operation. In this way, in the link mechanism 300, the forearm 301 becomes a drive arm that receives power from the cam mechanism 400 in response to the relative rotation of the planting claw device 50 and rotates back and forth, operating the link mechanism 300 to reciprocate the furrow making arm 200.

[0190] 24 to 28, the operation of the cam mechanism 400, the link mechanism 300, and the furrow making arm 200 in conjunction with the relative rotation of the planting claw device 50 will be described. For convenience, in FIGS. 24 to 28, the relative rotation of the planting claw device 50 is shown as the rotation of the rotary case 52 relative to the planting claw device 50 in a fixed position, that is, the change in the angular position of the rotary case 52 relative to the planting claw device 50 about the claw-side rotation axis O2 (the central axis P1 of the cam plate 410). As shown in FIGS. 24 to 28, during the relative rotation of the planting claw device 50, the rotary case 52 rotates counterclockwise relative to the planting claw device 50 when viewed from the left side (see arrow M1).

[0191] The state in which the guide roller 402 contacts the first arc cam surface portion 412 of the cam plate 410 corresponds to the standby position of the furrow making arm 200, and the state in which the guide roller 402 contacts the second arc cam surface portion 413 of the cam plate 410 corresponds to the furrow making position of the furrow making arm 200. In other words, in the relative rotation of the planting claw device 50, when the guide roller 402 contacts the first arc cam surface portion 412, the furrow making arm 200 is in the standby position, and when the guide roller 402 contacts the second arc cam surface portion 413, the furrow making arm 200 is in the furrow making position.

[0192] 24 shows the state in which the furrowing arm 200 is in the standby position. In the state shown in FIG. 24, the guide roller 402 is in contact with a position near the starting end of the first arc cam surface portion 412 in the rotation direction of the cam plate 410 relative to the planting claw device 50.

[0193] Figure 25 shows a state in which the rotary case 52 has rotated approximately 100° relative to the planting claw device 50 from the state shown in Figure 24. As shown in Figure 25, during the relative rotation of the planting claw device 50, while the guide roller 402 is in contact with the first arc cam surface portion 412, the rotational position of the link mechanism 300 is maintained, and the standby position of the furrow making arm 200 is maintained.

[0194] As the relative rotation of the planting claw device 50 progresses, the contact position of the guide roller 402 relative to the cam plate 410 moves from the first arc cam surface portion 412 to one of the linear cam surfaces 414 (the linear cam surface 414 on the rear side in the direction of movement of the guide roller 402 relative to the cam plate 410), causing the furrowing arm 200 to begin moving toward the furrowing posture. That is, as the guide roller 402 moves relatively from the first arc cam surface portion 412 to the linear cam surface 414, the guide roller 402 approaches the central axis P1 (the claw-side rotation axis O2) of the cam plate 410, and the roller support arm 403 rotates in a direction that raises the guide roller 402 (see arrow M2 in Figure 26). As a result, the link mechanism 300 rotates in a direction that tilts the front arm 301 forward, and the furrowing arm 200 gradually moves forward, that is, toward the side that assumes the furrowing posture.

[0195] 27, the groove making arm 200 assumes the groove making posture when the guide roller 402 reaches the second arc cam surface portion 413 from the terminal end of the linear cam surface 414. As shown in FIGS. 27 and 28, when the guide roller 402 is positioned at the second arc cam surface portion 413, the groove making arm 200 maintains the groove making posture.

[0196] Then, as the relative rotation of the planting claw device 50 progresses, the contact position of the guide roller 402 relative to the cam plate 410 moves from the second arc cam surface portion 413 to the other linear cam surface 414 (the linear cam surface 414 on the front side in the direction of movement of the guide roller 402 relative to the cam plate 410), and the furrowing arm 200 begins to move toward the standby position. That is, as the guide roller 402 moves relatively from the linear cam surface 414 to the first arc cam surface portion 412, the guide roller 402 moves away from the central axis P1 (the claw-side rotation axis O2) of the cam plate 410, and the roller support arm 403 rotates in a direction that lowers the guide roller 402 (see arrow M3 in Figure 28). As a result, the link mechanism 300 rotates in a direction that tilts the front arm 301 rearward, and the furrowing arm 200 gradually moves rearward, that is, toward the standby position.

[0197] Then, when the guide roller 402 reaches the first arc cam surface portion 412 from the end portion of the linear cam surface 414, the furrow making arm 200 returns to the standby position (see FIG. 24). The above-mentioned operation is repeated in accordance with the relative rotation of the planting claw device 50.

[0198] As described above, the furrowing arm 200 is configured to change its position and posture relative to the planting claw 72 in conjunction with the relative rotation of the planting claw device 50, which causes the planting claw 72 to move, via the link mechanism 300 and the cam mechanism 400. With this configuration, the shape of the cam surface 411 of the cam plate 410 adjusts the operating mode of the furrowing arm 200 in conjunction with the relative rotation of the planting claw device 50. Specifically, by adjusting the shape of the cam surface 411, it is possible to adjust, for example, the timing at which the furrowing arm 200 starts moving from the standby position to the furrowing position, the timing at which the furrowing arm 200 returns to the standby position, and the like.

[0199] The operation of the planting unit having the above-described configuration will be described with reference to Figures 29 to 35. The operation of the planting unit includes the planting operation of the seedling blocks 110 by the planting claw device 50, as well as the operation of making furrows and cutting the mulch film 250 by the furrow making arm 200 linked to the planting operation.

[0200] 30 to 35 are left side views of the planting unit, with the machine body moving leftward in each figure (see arrow N1). Also, in each of Figures 30 to 35, in order to show the displacement of the machine body of the planting unit relative to the field, for convenience, the seedling block 110 is shown only in a state where it is planted in the field.

[0201] The trajectory E1 shown by the dashed line in each of Figures 30 to 35 is the trajectory traced by the tip of the planting claw 72, i.e., the tip of the claw body 82. The trajectory E1 is a vertically elongated, approximately elliptical, closed (loop-shaped) trajectory. In detail, the trajectory E1 has a substantially elliptical shape with a convex bulge on the front side and a flattened trajectory on the rear side.

[0202] The trajectory E1 of the planting claw 72 is the trajectory of the machine body of the seedling transplanter 1 moving forward relative to the field. In other words, the trajectory E1 does not take into account the movement of the planting claw 72 relative to the field as the machine body moves forward, and is a stationary trajectory based on the machine body.

[0203] As shown in Figures 30 to 35, in the planting unit that moves forward as the machine body advances, the drive shaft 52a of the rotary case 52 maintains a substantially constant height position relative to the field scene 91. In other words, during the operation of the planting unit as the machine body advances, the case-side rotation axis O1 describes a trajectory E2 that is parallel to the field scene 91 (see Figure 30).

[0204] Figure 29 shows a graph illustrating the operation of the planting claw device 50 and the furrowing arm 200. In the graph shown in Figure 29, the horizontal axis shows the phase [deg] of the planting claw device 50 in the relative rotation of the planting claw device 50 around the claw-side rotation axis O2, that is, the relative angular position between the planting claw device 50 and the rotary case 52.

[0205] In Figure 29, graph Gr1, shown by a solid line, shows an example of the change in position of the furrow making arm 200 accompanying a change in the phase of the planting claw device 50, that is, the amount of rotation (arm rotation amount) [deg] of the roller support arm 403 caused by the cam plate 410. Graph Gr2, shown by a dashed line, shows an example of the change in height of the planting claw 72 accompanying a change in the phase of the planting claw device 50. Here, the height of the planting claw 72 (planting claw height) is the height of the tip of the planting claw 72 relative to a predetermined reference height corresponding to the field scene 91, and is expressed as a ± value, for example, with the predetermined height position as the reference (0 [mm]).

[0206] First, as shown in Figure 30, the planting claws 72 scrape the unit block portions 108 in accordance with the rotation of the rotary case 52 about the case-side rotation axis O1 and the relative rotation of the planting claw device 50. The state of the planting unit shown in Figure 30 is the state in the "scraping" range of the phase of the planting claw device 50 in the graph shown in Figure 29.

[0207] In the "scraping" range, the furrow making arm 200 is in a standby position. In other words, the guide roller 402 is in contact with the first arc cam surface portion 412 of the cam plate 410. In the operation of the cam mechanism 400, the position of the roller support arm 403 when the furrow making arm 200 is in the standby position is set to the reference position, that is, the rotation amount is 0 [deg]. In this way, the planting claws 72 scrape the seedling mat 100 at a predetermined timing when the furrow making arm 200 is in the standby position.

[0208] Furthermore, with regard to the planting claw height in the "scraping" range, the planting claw 72 is positioned at or near the height position h1 at the upper end of its lifting range. Note that graph Gr2, which shows the change in planting claw height, depicts a sine wave-like curve.

[0209] After the planting claws 72 have scraped the unit block portion 108, as shown in Figure 31, the planting claw device 50 rotates to move the planting claws 72 forward and downward of the guide rail 48. The state of the planting unit shown in Figure 31 is the state in the "downward" range of the phase of the planting claw device 50 in the graph shown in Figure 29.

[0210] In the "downward" range, the planting claw height gradually decreases as shown in graph Gr2. Also, in the "downward" range, when the phase of the planting claw device 50 reaches the predetermined first phase t1, the furrow making arm 200, which is in the standby position, begins to move toward the furrow making position. That is, the guide roller 402 moves from the first arc cam surface portion 412 to one of the linear cam surfaces 414, and the amount of arm rotation begins to increase as shown in graph Gr1.

[0211] During the "downward" range, the arm rotation amount gradually increases, and when the phase of the planting claw device 50 reaches the predetermined second phase t2, the arm rotation amount reaches the maximum value U1. In other words, the furrow making arm 200 assumes the furrow making posture.

[0212] As the relative rotation of the planting claw device 50 progresses with the furrowing arm 200 in the furrowing position, the tip of the furrowing arm 200 in the furrowing position reaches the field surface 91, as shown in Figure 32, and the furrowing arm 200 begins to penetrate (make a furrow). The timing of the furrowing arm 200 penetration corresponds to the timing at which the phase of the planting claw device 50 reaches the predetermined third phase t3 in the graph shown in Figure 29. From the third phase t3, the phase of the planting claw device 50 enters the "soil penetration" range. In the "soil penetration" range, when planting seedlings with the planting claw device 50, the furrowing arm 200 cuts the mulch film 250 and makes a furrow at the planting location in the field.

[0213] As shown in Figure 32, when the furrow making arm 200 penetrates into the field, the lower edge of the arm tip 202, which forms the tip of the furrow making arm 200, comes into contact with the field surface 91. As described above, the arm tip 202 is a plate-like portion that is linear in a side cross-sectional view (see Figure 22). The furrow making arm 200 then inserts the arm tip 202 into the field surface 91 in an upright position.

[0214] In this way, the furrow making arm 200 is arranged so that the arm tip 202 is in a standing state relative to the field scene 91 when the arm enters the field scene 91. Here, the standing state of the arm tip 202 relative to the field scene 91 is a state in which the angle α1 formed between the extension direction V1 of the arm tip 202, which is linear in a side cross-sectional view, and the field scene 91 is 45° or more, as shown in Figure 32. In the example shown in Figure 32, the angle α1 is approximately 60°.

[0215] In the "soil penetration" range, as shown in graph Gr2, the planting claw height continues to gradually decrease from the "descending" range, and when the planting claw 72 reaches the height position h2 at the lower end of its elevation range or a position nearby, the planting of the seedling block 110 is performed by the planting claw device 50. The state of the planting unit shown in Figure 33 is the state in the "planting" range of the phase of the planting claw device 50 in the graph shown in Figure 29.

[0216] That is, as shown in Figure 33, when the planting claw device 50 holds the seedling block 110, the pushing member 73 pushes out the seedling block 110 at a predetermined timing when the tip of the planting claw 72 is positioned in the field below the field surface 91 (see arrow R1). After planting the seedling block 110, the planting claw device 50 gradually rises until the planting claw 72 reaches the height position h1 of the raised end (see Figures 34 and 35).

[0217] Meanwhile, the furrowing arm 200 in the furrowing position begins moving toward the standby position when the phase of the planting claw device 50 reaches the predetermined fourth phase t4 within the "soil penetration" range. That is, the guide roller 402 moves from the second arc cam surface portion 413 to the other linear cam surface 414, and the amount of arm rotation begins to decrease, as shown in graph Gr1. Then, with respect to the phase of the planting claw device 50, the amount of arm rotation decreases from the middle of "soil penetration" through the range of "planting" and the subsequent "storage," and the furrowing arm 200 returns to the standby position when the phase of the planting claw device 50 reaches the predetermined seventh phase t7. The timing of the seventh phase t7 marks the end point of the "storage" phase of the planting claw device 50.

[0218] Then, the planting claws 72 return to the height position h1 at the upper end, and the furrowing arm 200 returns to the standby state, and the planting claws 72 begin scraping the unit block parts 108 as described above. The above-described operation of the planting unit is performed continuously as a cycle operation as the machine body moves forward.

[0219] In the example shown in graph Gr1 of Fig. 29, the furrow making arm 200 gradually moves toward the storage position from the timing of the fourth phase t4, and temporarily stops in the "planting" range when the phase of the planting claw device 50 reaches the predetermined fifth phase t5. After that, when the timing reaches the predetermined sixth phase t6 after planting is completed, it starts moving toward the storage position.

[0220] In this way, the groove making arm 200 is arranged to move from the groove making position through the groove making completion position in which it is stopped between the fifth phase t5 and the sixth phase t6, and then return to the standby position. In other words, the groove making arm 200 is arranged to perform a two-stage retraction operation to return from the groove making position to the standby position: a first retraction operation from the fourth phase t4 to the fifth phase t5, and a second retraction operation from the sixth phase t6 to the seventh phase t7.

[0221] When groove making arm 200 is caused to perform such a two-stage retraction operation, a third arc-shaped cam surface portion (not shown) is provided on cam plate 410 at a position where linear cam surface 414 is formed on the other side (on the left side in FIG. 23) of the phase of cam surface 411. The third arc-shaped cam surface portion is a surface portion having an arc shape centered at the position of central axis P1 of cam plate 410. The radius of the circumferential shape along which third arc-shaped cam surface portion follows is smaller than the radius of the circumferential shape along which first arc-shaped cam surface portion 412 follows and is larger than the radius of the circumferential shape along which second arc-shaped cam surface portion 413 follows.

[0222] In the operation of the planting unit as described above, the furrow making arm 200 is configured to perform a cyclical operation of returning from the furrow making position to the standby position after the planting of seedlings in the field is completed by the planting claws 72. In other words, seedlings are planted by the planting claw device 50 from the time when the furrow making arm 200 starts to move from the standby position toward the furrow making position until the time when the furrow making arm 200 returns to the standby position.

[0223] Furthermore, in the operation of the planting unit, the furrow making arm 200 is positioned so that, when in the furrow making position, its tip projects further forward than the planting claws 72 and enters the field scene 91 ahead of the planting claws 72. When planting seedlings using the planting claw device 50, the planting unit first makes furrows by applying the furrow making arm 200 to the field as shown in Figure 32, then applies the planting claws 72 to the field, and as shown in Figure 33, planting the seedlings, i.e., pushing out the seedling blocks 110, is performed when furrow making by the furrow making arm 200 is completed.

[0224] Furthermore, with regard to the furrow making operation of the furrow making arm 200, the furrow making arm 200 is arranged so as not to interfere with the seedling blocks 110, which are seedlings planted in the field, at least within the operating range in which the tip is positioned below the field surface 91. Specifically, as shown in Figures 32, 33 and 34, the furrow making arm 200 is arranged so that the arm tip 202 passes under the seedling blocks 110 (virtually placed seedling blocks 110) to be planted in a predetermined planting position in the field by the planting claw device 50 or the seedling blocks 110 planted in the field.

[0225] In Figures 32, 33, and 34, the trajectory E3 of the arm tip 202 of the furrow making arm 200 is shown by a two-dot chain line. Trajectory E3 indicates the trajectory of the lower edge of the arm tip 202. As shown by trajectory E3, the furrow making arm 200 penetrates the arm tip 202 into the field scene 91 from a position in front of the virtually placed seedling block 110 (Figures 32 and 33). The arm tip 202 then moves below the virtually placed seedling block 110, and when it reaches the rear of the virtually placed seedling block 110, the seedling block 110 is actually planted (see arrow R1 in Figure 33).

[0226] According to the trajectory E3, the furrow making arm 200, with the tip of the arm tip 202 positioned below and behind the planted seedling block 110, moves the arm tip 202 upward and away from the field scene 91 (Figure 34). After that, the furrow making arm 200 moves the arm tip 202 upward while gently moving it toward the front side of the seedling block 110 above the seedling block 110. The trajectory E3, above the seedling block 110, moves from the outside to the inside of the trajectory E1 of the planting claw 72 and intersects with the trajectory E1 (see intersection R2 in Figure 34).

[0227] In this way, the furrow making arm 200 moves the arm tip 202 from the front of the seedling block equivalent portion, passing under the seedling block equivalent portion with a gap, and around to the rear of the seedling block equivalent portion, relative to the portion where the seedling block 110 to be planted in the field will be located and the seedling block 110 that has actually been planted (hereinafter referred to as the "seedling block equivalent portion"). In other words, when the furrow making arm 200 returns from its lowering operation to its upper operation, it moves the arm tip 202 in a manner that makes a U-turn around the seedling block equivalent portion so that the trajectory E3 does not interfere with the seedling block equivalent portion. In the example shown in the graph of FIG. 29, the furrow making arm 200 reliably avoids contact with the seedling block 110 by performing the two-stage retraction operation as described above.

[0228] Furthermore, with regard to the operation of the furrow making arm 200, the movement trajectory of the tip of the furrow making arm 200 is set to trace a trajectory E3 that ensures space for the planting claw 72 located at the lowest end to push out the seedling block 110, which is the seedling held by the planting claw 72 together with the holding plate 74.

[0229] The furrow making arm 200 removes soil from the field along the trajectory of the arm tip 202, creating a furrow. The furrow making arm 200 acts on the field so that the portion of the soil removed by acting on the field, i.e., the furrowing portion, becomes the space where the seedling blocks 110 released from the planting claw device 50 will be located. In the trajectory E3 of the arm tip 202 of the furrow making arm 200, a position within the range surrounded by the approximately "U"-shaped folded portion at the lower end is secured as the space into which the seedling blocks 110 will be released when the furrow making by the furrow making arm 200 is completed.

[0230] The seedling transplanter 1 having the above-described configuration is equipped with a trajectory change device 270 in the planting unit that changes the movement trajectory of the furrow making arm 200 relative to the planting claws 72 to correspond to the planting pitch of the seedlings by the planting claws 72. The planting pitch of the seedlings by the planting claws 72 is the spacing between seedlings that are successively planted at a predetermined interval in the front-to-back direction in the field, i.e., the spacing between rows.

[0231] As described above, the row spacing is changed by the rotational speed of the rotary case 52, which is changed by the transmission 36 (see FIG. 3) in the row spacing transmission case 33. In this embodiment, the transmission 36 is configured to switch the row spacing between two stages: a relatively large row spacing (e.g., 40 cm) and a relatively small row spacing (e.g., 24 cm). If the trajectory of the furrow making arm 200 remains constant regardless of the row spacing, the seedling planting performance may decrease, or the furrow making torque on the soil may increase, resulting in a heavy load. Therefore, the trajectory change device 270 changes the trajectory of the furrow making arm 200 according to the row spacing.

[0232] The trajectory change device 270 is composed of a link mechanism 300 that supports the furrowing arm 200 relative to the planting claw device 50, including the planting claws 72. As described above, the link mechanism 300 is configured to operate in the form of a four-joint link with the axes (rotation axes) of the four support parts as nodes, and is configured to change the movement trajectory of the furrowing arm 200, which moves back and forth between the standby position and the furrowing position in accordance with the operation of the link mechanism 300, by changing the distance between the axes of the support parts in the link mechanism 300.

[0233] The link mechanism 300 as the trajectory change device 270 is configured to change the distance between the support parts of the two link arms, the front arm 301 and the rear arm 302, on the furrowing arm 200 side, thereby changing the movement trajectory of the furrowing arm 200 relative to the planting claws 72. In this embodiment, the inter-axial distance L1 (see Figure 20) between the rotation axis Q3 of the front moving shaft support part 313 and the rotation axis Q4 of the rear moving shaft support part 314 corresponds to the distance between the support parts of the two link arms on the furrowing arm 200 side.

[0234] The inter-axis distance L1 changes by adjusting the position of the rear moving journal portion 314 relative to the front moving journal portion 313. As described above, the position of the rear moving journal portion 314 is continuously adjusted within the range of the length of the hole portion 204b, through which the bolt 323 passes, at two locations above and below the rear moving journal portion 314, depending on the fixed position of the connecting plate 310 relative to the support plate 204. The position adjustment mechanism for the rear moving journal portion 314 functions as a mechanism for changing the trajectory of the groove making arm 200 in the link mechanism 300, which serves as the trajectory change device 270.

[0235] In the planting unit shown in Figures 18 and 20, the bolt 323 for fixing the connecting plate 310 to the support plate 204 is positioned at the rear end of the hole 204b, and the rear moving shaft support part 314 is spaced apart from the front moving shaft support part 313 (the most distant state). In other words, the planting unit shown in Figures 18 and 20 is in a state where the inter-shaft distance L1 is at its longest. Note that Figure 18 shows the state in which the furrow making arm 200 is in the furrow making position, and Figure 20 shows the state in which the furrow making arm 200 is in the standby position. The inter-shaft distance L1 is maintained at a constant value regardless of the position of the furrow making arm 200.

[0236] On the other hand, the planting unit shown in Figures 36 and 37 has the bolt 323 positioned at the front end of the hole 204b, and the rear moving shaft support part 314 brought closer to the front moving shaft support part 313 (closest position). In other words, the planting unit shown in Figures 36 and 37 is in a state where the inter-shaft distance L1 is at its shortest. Note that Figure 36 shows the state where the furrow making arm 200 is in a furrow making position, and Figure 37 shows the state where the furrow making arm 200 is in a standby position. Hereinafter, the state where the inter-shaft distance L1 is long as shown in Figures 18 and 20 is referred to as the "shaft support part separated state," and the state where the inter-shaft distance L1 is short as shown in Figures 36 and 37 is referred to as the "shaft support part close position state."

[0237] As the inter-axis distance L1 changes, the operating mode of the furrowing arm 200, which reciprocates in the planting unit, changes. Figure 38A shows the operating mode of the furrowing arm 200 in a state where the shaft support is separated, and Figure 38B shows the operating mode of the furrowing arm 200 in a state where the shaft support is close. In each of Figures 38A and 38B, the furrowing arm 200 in the furrowing position is shown in a solid line, the furrowing arm 200A in the standby position is shown in a dashed line, and the furrowing arm 200B between the standby position and the furrowing position is shown in a dashed line.

[0238] As shown in Figures 38A and 38B, a change in the inter-shaft distance L1 changes the operating range of the furrowing arm 200 that reciprocates in the planting unit. That is, the operating range of the furrowing arm 200 in a side view is widened by switching from the pivot support part distant state shown in Figure 38A to the pivot support part close state shown in Figure 38B. In the pivot support part close state, the operating range of the furrowing arm 200 is widened mainly in the vertical direction in the figure. Either the pivot support part distant state or the pivot support part close state, which changes the operating mode of the furrowing arm 200 in this way, is used depending on the spacing between plants.

[0239] Figure 39 shows the movement trajectories of the planting claw 72 and furrow making arm 200 when the planting unit is in proximity to the pivot support and the plant spacing is relatively large (e.g., 40 cm) with a spacing dimension S1. In Figure 39, the trajectory W1 shown by the dashed line is the trajectory traced by the tip of the planting claw 72, i.e., the tip of the claw body 82. The trajectory W2 shown by the dashed line is the trajectory traced by the tip protrusion 202a of the arm tip 202 of the furrow making arm 200.

[0240] The trajectory W1 of the planting claw 72 and the trajectory W2 of the furrow making arm 200 are the trajectories of the planting claw 72 and the furrow making arm 200, respectively, that perform predetermined operations while moving forward relative to the field together with the forward-moving machine body of the seedling transplanter 1. In other words, the trajectories W1 and W2 take into account the movement of the planting claw 72 and the furrow making arm 200 relative to the field as the machine body moves forward, and are trajectories based on the field side.

[0241] As described above, the planting claw 72, which draws a loop-shaped trajectory (see trajectory E1 in Figure 30) when the machine body is used as the reference, moves forward relative to the field, and as shown by trajectory W1 in Figure 39, it repeatedly draws a trajectory that curves downward at the front due to a downward movement while moving forward, and a trajectory that curves upward at the front due to an upward movement while moving forward. The trajectory W1 has a vertically elongated loop-shaped trajectory portion W1a at the turning point from the downward movement to the upward movement.

[0242] The planting claws 72 move periodically to trace a loop-shaped trajectory when the machine body is used as the reference, and the distance of one cycle of the trajectory W1, which takes forward movement into account in the field, corresponds to the spacing S1. In other words, the planting claws 72 perform a predetermined planting operation as the machine body moves forward, thereby repeating the movement of tracing the trajectory W1 shown in Figure 39.

[0243] The trajectory W2 of the furrow making arm 200 is a trajectory that includes the movement of the planting claw 72 and the periodic reciprocating movement of the furrow making arm 200 relative to the planting claw 72. Similarly to the trajectory W1 of the planting claw 72, the trajectory W2 of the furrow making arm 200 generally has a downward-facing trajectory portion, an upward-facing trajectory portion, and a loop-shaped trajectory portion W2a that turns back. The loop-shaped trajectory portion W2a of the trajectory W2 includes a portion corresponding to the trajectory E3 of the furrow making arm 200, which moves the arm tip 202 in a U-turn around the seedling block equivalent portion so as not to interfere with the seedling block equivalent portion, as described above (see Figures 33 and 34).

[0244] Therefore, the seedling block equivalent portion is located within the looped trajectory portion W2a of the trajectory W2 of the furrow making arm 200. It is preferable that the looped trajectory portion W2a of the trajectory W2 of the furrow making arm 200 passes close to the seedling block equivalent portion without interfering with the seedling block equivalent portion. In other words, it is preferable that the trajectory portion W2a of the turning back portion of the trajectory W2 of the furrow making arm 200 draws the minimum necessary loop shape so as not to interfere with the seedling block equivalent portion (see the area surrounded by the dashed circle X1 in Figure 39).

[0245] FIG. 40 shows the movement loci of the planting claws 72 and the furrow making arm 200 when the planting unit is in the pivotal support portion proximity state and the plant spacing is a relatively small plant spacing dimension S2 (for example, 24 cm).

[0246] When the spacing between plants is relatively small, the planting movement of the planting claws 72 relative to the forward movement of the machine body is large (the movement is fast). Therefore, as shown in Figure 40, compared to when the spacing between plants is relatively large (Figure 39), the distance for one cycle corresponding to the spacing dimension S2 is shorter, and the loop-shaped trajectory portion W1a of the trajectory W1 of the planting claws 72 is larger.

[0247] Therefore, as shown in Figure 40, when the spacing between plants is relatively small, the loop-shaped trajectory portion W2a, which positions the seedling block equivalent portion inside, becomes large for the trajectory W2 of the furrow making arm 200. In other words, the trajectory W2 of the furrow making arm 200 describes a trajectory that detours around the seedling block equivalent portion (see the portion surrounded by the dashed circle X2 in Figure 40).

[0248] Increasing the trajectory portion of the trajectory W2 of the furrow making arm 200 around the portion corresponding to the seedling block corresponds to increasing the size of the portion of the field excavated by the furrow making arm 200, i.e., the transplant hole for transplanting the seedlings. If the transplant hole becomes larger, problems may arise such as a decrease in seedling planting performance and an increase in the torque of the furrow making arm 200, which increases the load.

[0249] Therefore, when the spacing between plants is relatively small, the position adjustment mechanism of the rear moving pivot support part 314 in the link mechanism 300 switches the state of the planting unit from a pivot support close state (see Figure 38B) in which the operating range of the furrow making arm 200 is relatively wide to a pivot support distant state (see Figure 38A) in which the operating range of the furrow making arm 200 is relatively narrow. As a result, the trajectory portion of the trajectory W2 of the furrow making arm 200 around the part corresponding to the seedling block becomes smaller.

[0250] Figure 41 shows the movement loci of the planting claws 72 and furrow making arm 200 when the planting unit is in the pivotally separated state and the plant spacing is a relatively small plant spacing S2 (e.g., 24 cm). As shown in Figure 41, when the planting unit is in the pivotally separated state, the loop-shaped locus portion W2a of the locus W2 of the furrow making arm 200 when the plant spacing is relatively small becomes smaller. In other words, similar to the locus W2 of the furrow making arm 200 shown in Figure 39, the locus portion W2a of the turning part of the locus W2 of the furrow making arm 200 is formed into the minimum necessary loop shape so as not to interfere with the portion corresponding to the seedling block, preventing the transplant hole from becoming larger than necessary (see the area surrounded by the dashed circle X3 in Figure 41).

[0251] In this way, the trajectory W2 of the furrow making arm 200 is optimized by using either the close-to-center or far-away state of the planting unit depending on the size of the plant spacing, which is changed by the transmission 36 (see Figure 3) inside the plant spacing transmission case 33. Note that if the planting unit is in the far-away state when the plant spacing dimension S1 is relatively large (for example, 40 cm), the loop-shaped portion of the trajectory W2 of the furrow making arm 200 becomes smaller, making it more likely to interfere with the part corresponding to the seedling block.

[0252] According to the seedling transplanter 1 of this embodiment having the above-described configuration, interference of the furrow making arm 200 with the planted seedlings can be suppressed, thereby achieving good planting performance.

[0253] The planting unit of the seedling transplanter 1 is configured so that the furrow making arm 200 can be positioned in two positions: a standby position when the seedling mat 100 is about to be cut, and a furrow making position in which the arm is moved forward relative to the planting claws 72. This configuration allows the furrow making arm 200 to start furrowing before the planting claws 72 plant the seedlings, while avoiding interference with the guide rails 48. This allows for greater freedom in the position of the furrow making arm 200 relative to the planting claws 72, making it possible to accommodate changes in seedling planting conditions. This improves seedling planting accuracy and eliminates problems such as increased furrowing torque on the soil and interference of the furrow making arm 200 with planted seedlings, resulting in better planting performance.

[0254] The furrow making arm 200 is also configured to perform a cyclical movement from a furrow making position to a standby position after the planting of seedlings by the planting claws is completed. This configuration allows the relative position and posture of the furrow making arm 200 with respect to the planting claws 72 to be transitioned after the seedlings are planted, enabling furrow making operations suitable for planting seedlings. In particular, by configuring the furrow making arm 200 to perform a two-stage retraction movement as described above, it becomes possible to perform furrow making operations more suitable for planting seedlings. Furthermore, by returning the furrow making arm 200 to the standby position after furrowing is completed, it is possible to prevent the furrow making arm 200 from interfering with the guide rail 48, for example, when the planting claws 72 scrape the next unit block portion 108.

[0255] Furthermore, the furrow making arm 200 is positioned so that its tip projects forward of the planting tines 72 when in the furrow making position, entering the field surface before the planting tines 72. With this configuration, the furrow making arm 200 creates furrows when the planting tines 72 plant seedlings. This ensures that the seedlings are planted reliably in the furrows created by the furrow making arm 200, reducing planting resistance. Reducing the resistance to planting seedlings makes it easy to ensure that the planting tines 72 and their supporting structure have the necessary strength to withstand planting resistance. This allows for the planting unit and, in turn, the seedling planting device 43 to be made smaller and lighter. Furthermore, in a field where a mulch film 250 is laid on the field surface 91, the furrow making arm 200 cuts the mulch film 250 and creates furrows before the planting tines 72 enter the field surface, ensuring smooth and stable seedling planting.

[0256] Furthermore, when the arm tip 202 is positioned below the field surface, the furrow making arm 200 is configured to trace a path (see path E3 in Figure 32) that passes near the seedling blocks 110 planted in the field without interfering with them. This configuration reduces the furrow making torque and the drive torque of the planting claw device 50 by creating a furrow at a minimum depth that does not interfere with the seedling blocks 110, thereby reducing the size and weight of the planting unit and, in turn, the seedling planting device 43. Furthermore, this torque reduction facilitates ensuring the drive force and strength of the drive system of the planting claw device 50. Furthermore, because the furrow making arm 200 is prevented from creating a furrow deeper than necessary, the planting posture of the seedling blocks 110 in the field is stabilized, resulting in good planting performance.

[0257] Furthermore, the furrow making arm 200 is configured to change its position and posture in conjunction with the operation of the planting claws 72. With this configuration, the speed of the furrow making arm 200 is automatically changed in conjunction with the speed change of the planting claws 72 caused by changes in the plant spacing by the transmission 36 in the plant spacing transmission case 33, so it is not necessary to adjust the operation timing of the furrow making arm 200 when the plant spacing is changed.

[0258] Furthermore, the furrow making arm 200 is configured to change its position and posture in conjunction with the movement of the planting claws 72 by a cam mechanism 400 including a cam plate 410. With this simple configuration, the relative rotation of the planting claw device 50 can be used as the movement for linking the furrow making arm 200 to the movement of the planting claws 72. This allows the furrow making arm 200 to be linked to the movement of the planting claws 72 while achieving a compact configuration of the seedling planting device 43 without the need for a separate drive source or the like.

[0259] Furthermore, the furrow making arm 200 is configured so that the plate-shaped arm tip 202 stands upright relative to the field surface when it enters the field. This configuration reduces the contact area of ​​the furrow making arm 200 with the field surface when it enters the field, thereby reducing the furrow making torque of the furrow making arm 200 and the drive torque of the planting claw device 50, thereby making it possible to reduce the size and weight of the seedling planting device 43. In particular, the furrow making arm 200 can effectively reduce the furrow making torque of the furrow making arm 200 and the drive torque of the planting claw device 50 by aligning the linear extension direction (see arrow Y1 in Figure 22) of the arm tip 202 in a side cross-sectional view with the trajectory of the tip protrusion 202a during the furrow making operation. Furthermore, in the case of a field in which a mulch film 250 is stretched over the field surface 91, the arm tip 202 can smoothly cut the mulch film 250, allowing for smooth and stable planting of seedlings.

[0260] Furthermore, groove making arm 200 has a downwardly convex mountain shape at the bottom of arm tip 202. With this configuration, the mulch film 250 can be cut starting from the contact point of the lower end of arm tip 202 with the mulch film 250, and groove making arm 200 can smoothly cut mulch film 250.

[0261] Furthermore, the furrow making arm 200 is configured so that the movement locus of the arm tip 202 describes a locus that ensures space for the planting claw 72 located at the lowest end to push out the seedling block 110 held by the planting claw 72. With this configuration, by setting the furrow depth made by the furrow making arm 200 to the minimum depth necessary to push out the seedling block 110, the furrow making torque by the furrow making arm 200 can be reduced, and the strength of the furrow making arm 200 can be easily ensured. Furthermore, since the seedling block 110 can be reliably planted in the portion furrowed by the furrow making arm 200, good planting performance can be achieved.

[0262] The furrowing arm 200 also has an arm body 201 that is offset to one side in the left-right direction relative to the planting claw 72, and an arm tip 202 that is provided at the tip of the arm body 201. With this configuration, the arm body 201 of the furrowing arm 200 is offset to the left-right direction relative to the planting claw 72, so the furrowing arm 200 can be laid out so that the arm body 201 overlaps the planting claw 72 in a side view. This reduces the volume of the portion of the furrowing arm 200 that is embedded in the soil, thereby reducing the furrowing torque of the furrowing arm 200 and making it easy to ensure the strength of the furrowing arm 200. Furthermore, because the arm body 201 does not interfere with the planting claw 72 during the furrowing operation of the furrowing arm 200, the degree of freedom of movement of the furrowing arm 200 in relation to the planting claw 72 can be increased, making it possible to bring the furrowing operation of the furrowing arm 200 closer to ideal operation.

[0263] The furrow making arm 200 also has an auxiliary arm 203 located offset from the planting claw 72 on the opposite side of the arm main body 201 in the left-right direction, and the arm main body 201, arm tip 202, and auxiliary arm 203 form a roughly "U" shape. This configuration allows the furrow making arm 200 to achieve good furrow making performance. Furthermore, in a field where a mulch film 250 is laid out on the field surface 91, the arm main body 201 and auxiliary arm 203 can cut the mulch film 250 from both the left and right sides of the planting claw 72. This ensures that the mulch film 250 can be reliably cut and removed (peeled off) from the planting portion of the planting claw 72, reducing the amount of mulch film 250 remaining and resulting in good planting performance.

[0264] In addition, in order to accommodate changes in the spacing between plants, the seedling transplanter 1 is equipped with a trajectory change device 270 as a means for changing the movement trajectory of the furrow making arm 200 relative to the planting claws 72. With this configuration, the trajectory of the furrow making arm 200 can be adjusted to an optimal trajectory according to soil conditions, seedling conditions, etc., ensuring planting performance under various conditions.

[0265] Furthermore, the trajectory change device 270 can change the trajectory of the arm tip 202 of the furrow making arm 200 so that it traces a substantially constant trajectory by switching between the above-mentioned spacing between the plants, such as the spacing between the plants S1 (e.g., 40 cm) and the spacing between the plants S2 (e.g., 24 cm). This prevents the transplant hole from becoming larger than necessary, thereby achieving good planting performance and planting accuracy and preventing the furrow making load of the furrow making arm 200 from becoming excessively large. In this way, the trajectory change device 270 can set the trajectory of the furrow making arm 200 to an optimal trajectory in accordance with the spacing between the plants, thereby preventing problems such as the trajectory of the furrow making arm 200 becoming larger than necessary when the spacing between the plants is relatively small, as described above (see the area surrounded by the dashed circle X2 in Figure 40).

[0266] In addition, the trajectory change device 270 is configured with a link mechanism 300 that supports the furrowing arm 200 relative to the planting claw device 50. With this configuration, the trajectory of the furrowing arm 200 can be changed by changing the link ratio of the link mechanism, making it possible to easily change the trajectory.

[0267] Furthermore, the link mechanism 300 serving as the trajectory change device 270 is configured to change the trajectory of the groove making arm 200 by changing the inter-axis distance L1 (see FIG. 20), which is the distance between the support portions of each link arm of the front arm 301 and the rear arm 302 on the groove making arm 200 side. With this configuration, the trajectory change device 270 can be realized with a simple configuration. Also, the trajectory of the groove making arm 200 can be changed by the easy operation of changing the support position of one of the link arms. Furthermore, with the adjustment mechanism for the inter-axis distance L1, the changed state of the trajectory of the groove making arm 200 can be easily confirmed by visually checking the support position of the link arm.

[0268] Furthermore, the link mechanism 300 is configured so that the inter-axis distance L1 is adjusted by the fixed position of the connecting plate 310, on which the rear moving pivot support portion 314 is provided, relative to the furrowing arm 200. With this configuration, the trajectory of the furrowing arm 200 can be easily changed without replacing parts. Furthermore, the bolt 323 for fixing the connecting plate 310 to the furrowing arm 200 is provided so as to be operable from the left and right outer sides of the planting claw device 50, so that the bolt 323 can be easily operated, and the trajectory of the furrowing arm 200 can be easily changed.

[0269] In this embodiment, the adjustment mechanism for the center distance L1 is configured such that the hole 204b in the groove making arm 200 through which the bolt 323 passes is an elongated hole, allowing for stepless adjustment. However, the present invention is not limited to this configuration. For example, the groove making arm 200 may be configured such that multiple holes through which the bolt 323 passes are provided at predetermined intervals in the position adjustment direction of the rear moving journal support unit 314. Specifically, for example, in the case of supporting the above-described 40 cm and 24 cm spacings, two holes through which the bolt 323 passes are formed in the support plate 204: one corresponding to the journal support unit close state and one corresponding to the journal support unit far state. This configuration makes it possible to adjust the center distance L1 in steps to a preset value, thereby enabling the center distance L1 to be set to an appropriate value corresponding to the switching state between long and short spacings.

[0270] The planting claw device 50 also has digging claws 76 below the holding plate 74. With this configuration, the digging claws 76 dig the field before the holding plate 74, so even if the field has relatively hard soil, for example, the contact resistance of the holding plate 74 with the field can be reduced, and deformation and damage to the holding plate 74 can be suppressed. Furthermore, if a mulch film 250 is present in the field, the digging claws 76 can prevent the mulch film from becoming tangled around the holding plate 74.

[0271] [Other embodiments] Another embodiment of the planting unit according to the present invention will be described with reference to Figures 42 to 46. In this embodiment, the same names or symbols are used for components that are common to or correspond to the above-described embodiments, and descriptions of overlapping content will be omitted as appropriate. The planting unit according to this embodiment differs from the planting unit according to the above-described embodiments in the configuration of the furrow making arm.

[0272] The furrowing arm 500 according to this embodiment is configured longitudinally, and is provided so that its longitudinal direction is aligned with the claw extension direction. The furrowing arm 500 is provided near the planting claw 72 relative to the planting claw device 50. The furrowing arm 500 is movably supported by the link mechanism 300 relative to the planting claw device 50, and is provided so as to move relative to the planting claw 72.

[0273] The furrowing arm 500 is configured to have a generally "T" shape in plan view as a whole, with portions located on the left and right outer sides of the planting claw device 50 and a portion located below the planting claw device 50. The furrowing arm 500 has an arm main body 501 and an arm tip 502 as portions forming the generally "T" shape. These portions that make up the furrowing arm 500 are provided as plate-like portions having predetermined shapes.

[0274] The furrowing arm 500 has as its constituent members a support plate 204 that forms the support base of the furrowing arm 500, and a cutter member 505. The furrowing arm 500 has the same support structure for the support plate 204 and the planting claw device 50 by the support plate 204 as the furrowing arm 200 of the above-described embodiment. The support plate 204 and the cutter member 505 are connected and fixed to each other to form an integrated furrowing arm 500.

[0275] The cutter member 505 is a bent plate-like member that is roughly "T" shaped in a plan view, and forms the main body of the groove making arm 500. The cutter member 505 has an arm portion 505a and a front surface portion 505b as surfaces that form the roughly "T" shape (see FIG. 45).

[0276] The arm portion 505a has a generally "L"-shaped bent shape with the corners facing downward and rearward in a left-side view. The arm portion 505a has a base portion 505c forming the rear side of the generally "L" shape in a side view, an intermediate inclined surface portion 505d extending forward and inward to the left and right from the lower end of the base portion 505c, and a tip-side arm portion 505e extending forward from the tip side of the base portion 505c. A front surface portion 505b is provided in front of the tip-side arm portion 505e. In the arm portion 505a, the intermediate inclined surface portion 505d and the tip-side arm portion 505e form the lower side of the generally "L" shape in a side view.

[0277] The arm main body 501 includes a rear main body 506, which is a portion located outwardly of the planting claw 72 in the left-right direction, and a front main body 507, which is a portion located within the width of the planting claw 72 in the left-right direction. The arm main body 501 is a plate-shaped portion whose thickness direction is roughly in the left-right direction, and is formed by the support plate 204 and the arm portion 505a of the cutter member 505.

[0278] The cutter member 505 is fixed to the support plate 204 with the upper part of the base 505c overlapping the front end of the support plate 204 from the outside. The base 505c has a longitudinal shape that is long in the vertical direction, and its rear part extends downward from the front end of the support plate 204.

[0279] The cutter member 505 is fixed to the support plate 204 by two bolts 206. The two bolts 206 are located on both sides in the width direction of the front part of the support plate 204, at the overlapping portion of the base 505c of the cutter member 505 and the support plate 204. The bolts 206 pass through holes 505f formed in the upper part of the base 505c and are screwed into threaded holes formed in the front end part of the support plate 204.

[0280] The hole 505f through which the bolt 206 passes is an elongated hole with its longitudinal direction aligned with the direction in which the cutter member 505 extends from the support plate 204. This makes it possible to adjust the fixed position of the cutter member 505 relative to the support plate 204 in the extension direction.

[0281] Of the arm main body 501, the main body rear part 506 is a part located outside the planting claws 72 in the left-right direction. Therefore, as shown in Figure 43, the main body rear part 506 is a part formed by the support plate 204, the base part 505c of the cutter member 505, and the rear part of the intermediate inclined surface part 505d.

[0282] Furthermore, the front body part 507 of the arm body part 501 is a part located within the width range of the planting claw 72 in the left-right direction. Therefore, as shown in Figure 43, the front body part 507 is a part formed by the front part of the intermediate inclined surface part 505d of the cutter member 505 and the tip side arm part 505e.

[0283] In this way, the arm main body 501 has a front main body part 507 that is positioned in the same left-right direction as the planting claws 72, and the holding plate 74 and digging claws 76 located below the planting claws 72, and is arranged so that a portion of these components overlaps in a plan view. The front main body part 507 is positioned below the planting claws 72, holding plate 74, etc.

[0284] The tip arm portion 505e of the cutter member 505 is a plate-like portion with a thickness in the left-right direction, a straight line along the front-rear direction in a plan view, and a substantially constant width in a side view. The tip arm portion 505e is located approximately in the center of the planting claw 72 in the left-right direction. When the furrowing arm 500 is in the furrowing position, the tip arm portion 505e has a majority of its front side positioned forward of the tip of the planting claw 72. Note that Figure 43 shows the furrowing arm 500 in the furrowing position.

[0285] As described above, the arm main body portion 501 having the rear main body portion 506 and the front main body portion 507 extends downward from the rear to the front by the base portion 505c at the front of the portion located on the left and right outer sides of the planting claw device 50, and gradually moves inward on the left and right (upward in Figure 43) by the intermediate inclined surface portion 505d, and has a shape in which the tip arm portion 505e extends forward below the planting claw 72.

[0286] The arm tip 502 is provided on the tip side of the arm main body 501. The arm tip 502 is located forward of the tip of the excavation claw 76 when the groove making arm 500 is in the groove making position (see Figure 42), and is located below the tip of the excavation claw 76 when the groove making arm 500 is in the standby position (see Figure 44). The arm tip 502 is a plate-shaped portion that protrudes on both the left and right sides of the tip-side arm portion 505e of the cutter member 505 that forms the front part of the arm main body 501, and is formed by the front surface portion 505b of the cutter member 505.

[0287] The arm tip 502 has an inclined surface that slopes downward toward the front with respect to a direction perpendicular to the claw extension direction in a side view. The arm tip 502 is a plate-like portion that is linear in a side cross-sectional view (see FIG. 46). FIG. 46 is a cross-sectional view of the front part of the groove making arm 500, and is a left side cross-sectional view at the center position in the left-right direction (plate thickness direction) of the tip-side arm portion 505e. As shown in FIG. 46, the arm tip 502 has a linear shape with a predetermined direction (see arrow Z1) as the extension direction in a side cross-sectional view.

[0288] The lower edge of arm tip 502 forms tip protrusion 502a that protrudes slightly downward relative to the tip of arm main body 501. Arm tip 502 has a downwardly convex mountain shape at its lower edge, with apex 502c formed by a pair of oblique sides 502b. Apex 502c is an obtuse-angled corner formed by the pair of oblique sides 502b.

[0289] With the configuration including the groove making arm 500 according to this embodiment, the cutting width wd1 (see FIG. 43) of the mulch film 250 can be made narrower than the cutting width wd2 (see FIG. 19) of the above-described substantially "U"-shaped groove making arm 200. Here, the cutting width wd1 of the groove making arm 500 is the dimension of the left-right width of the arm tip 502, and the cutting width wd2 of the groove making arm 200 is the dimension in the left-right direction between the outer side surface of the outer surface portion 205a and the inner side surface of the inner surface portion 205c. As a result, when the mulch film 250 is cut by the groove making arm 500, the width of the scraps of the mulch film 250 can be shortened, and the scraps can be prevented from interfering with the planted seedlings.

[0290] The torn pieces of mulch film 250 are the remaining pieces of film that remain connected to the main body of the film (in a double-door manner) on both the left and right sides of the planted seedlings when the mulch film 250 is cut linearly in the front-to-rear direction by the arm main body 501 of the groove making arm 500. In this regard, with the U-shaped groove making arm 200, the mulch film 250 is cut in the front-to-rear direction by the arm main body 201 and the auxiliary arm 203, so that the torn pieces of mulch film 250 are wide remaining pieces whose rear side is connected to the main body of the film.

[0291] Furthermore, the T-shaped furrow making arm 500 allows for less soil to be pushed back compared to the U-shaped furrow making arm 200, allowing for a relatively large amount of soil to be covered around the planted seedlings.

[0292] Furthermore, in the case of the U-shaped furrow making arm 200, the arm main body 201 and the auxiliary arm 203 are configured to be positioned on the left and right outer sides of the planting claws 72, so the furrow making arm 200 can be brought closer to the planting claws 72. This allows the cut length (length in the front-to-back direction) of the mulch film 250 to be relatively short, and the length of the holes in the mulch film 250 can be shortened.

[0293] In contrast, in the case of the T-shaped furrow making arm 500, the front part of the arm body 501 is positioned below the center of the planting claws 72, so that the furrow making arm 500 is positioned relatively far from the planting claws 72 to avoid interference with the components of the planting claw device 50. This allows the cut length of the mulch film 250 to be relatively long, and the length of the holes in the mulch film 250 to be long.

[0294] Furthermore, similar to the U-shaped furrow making arm 200 described above, the furrow making arm 500 is configured so that the arm tip 502 stands upright relative to the field surface when it enters the field surface, thereby reducing the furrow making torque and the drive torque of the planting claw device 50. In particular, by aligning the linear extension direction (see arrow Z1 in Figure 46) of the arm tip 502 in a side cross-sectional view with the trajectory of the tip protrusion 502a during the furrow making operation, the furrow making torque and the like can be effectively reduced. Furthermore, the arm tip 502 can smoothly cut the mulch film 250, and in particular, the mountain-shaped lower part of the arm tip 502 provides a smooth cutting action on the mulch film 250.

[0295] The seedling transplanter according to the present invention described above using the embodiments is not limited to the above-mentioned embodiments, and various aspects can be adopted within the scope of the spirit of the present invention.

[0296] The present technology can be configured as follows: The configurations described below can be selected and combined as desired. (1) A seedling transplanter that cuts off a seedling mat placed on a seedling carrier one by one with a planting claw and plants the seedlings continuously in a field, A groove making arm provided near the planting claw and configured to move relative to the planting claw; A trajectory change device that changes the movement trajectory of the furrow making arm relative to the planting claws in order to correspond to the planting pitch of the seedlings by the planting claws. A seedling transplanter characterized by: (2) The groove forming arm is configured to change its position and posture relative to the planting claw in conjunction with the operation of the planting claw. The seedling transplanter according to (1) above, characterized in that (3) The trajectory change device is configured by a link mechanism that supports the furrowing arm with respect to the planting claw device including the planting claw. The seedling transplanter according to (1) or (2) above, characterized in that: (4) The link mechanism includes two link arms whose one end side is rotatably supported on the planting claw device side and whose other end side is rotatably supported on the groove making arm side, The trajectory change device changes the distance between the support parts of the two link arms on the furrowing arm side to change the movement trajectory of the furrowing arm relative to the planting claws. The seedling transplanter according to (3) above, characterized in that (5) The furrow making arm has a relative position and posture with respect to the planting claws: a standby position, which is a position and posture when the planting claws cut the seedling mat, and a furrow making position in which the arm moves forward relative to the planting claws when planting seedlings in the field; and is configured to perform a cyclical movement from the furrow making position back to the standby position after the planting claws have finished planting seedlings in the field. The seedling transplanter according to any one of (1) to (4) above, characterized in that: (6) The furrowing arm is configured so that, when in the furrowing position, its tip protrudes forward of the planting claws and enters the field surface ahead of the planting claws. The seedling transplanter according to (5) above, characterized in that (7) The furrow making arm is provided so as not to interfere with seedlings planted in the field at least in the operating range in which the tip end is positioned below the field surface. The seedling transplanter according to any one of (1) to (6) above, characterized in that: [Explanation of symbols]

[0297] 1 Seedling transplanter 3 Seedling transplant device 42 Seedling stand 50 Planted nail device 52 Rotary Case 72 Planting Claw 91 Field scene 100 seedling mats 110 seedling block 200 Grooving arm 201 Arm body 202 Arm tip 203 Auxiliary arm 270 Trajectory Changer 300 Link Mechanism 301 Front arm (link arm) 302 Rear arm (link arm) 313 Front moving axis support 314 Rear moving shaft support 400 Cam mechanism 410 Cam Plate (Cam) 500 Grooving arm 501 Arm body 502 Arm tip 506 Rear of main body 507 Front of main body

Claims

1. A seedling transplanter that cuts off a seedling mat placed on a seedling carrier one by one with a planting claw and plants the seedlings continuously in a field, A groove making arm provided near the planting claw and configured to move relative to the planting claw; A trajectory change device that changes the movement trajectory of the furrow making arm relative to the planting claws in order to correspond to the planting pitch of the seedlings by the planting claws. A seedling transplanter characterized by:

2. The groove forming arm is configured to change its position and posture relative to the planting claw in conjunction with the operation of the planting claw.

2. The seedling transplanter according to claim 1 .

3. The trajectory change device is configured by a link mechanism that supports the furrowing arm with respect to the planting claw device including the planting claw.

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

4. The link mechanism includes two link arms whose one end side is rotatably supported on the planting claw device side and whose other end side is rotatably supported on the groove making arm side, The trajectory change device changes the distance between the support portions of the two link arms on the furrowing arm side to change the movement trajectory of the furrowing arm relative to the planting claws.

4. The seedling transplanter according to claim 3.

5. The furrow making arm has a relative position and posture with respect to the planting claws: a standby position, which is a position and posture when the planting claws cut the seedling mat, and a furrow making position in which the arm moves forward relative to the planting claws when planting seedlings in the field; and is configured to perform a cyclical movement from the furrow making position back to the standby position after the planting claws have finished planting seedlings in the field.

2. The seedling transplanter according to claim 1 .

6. The furrowing arm is configured so that, when in the furrowing position, its tip protrudes forward of the planting claws and enters the field surface ahead of the planting claws.

6. The seedling transplanter according to claim 5.

7. The furrow making arm is provided so as not to interfere with seedlings planted in the field at least in the operating range in which the tip end is positioned below the field surface.

7. The seedling transplanter according to claim 5 or 6.

Images