Seedling transplanter

Abstract

To suppress interference of a grooving arm with a planted seedling in a seedling transplanter; and to obtain excellent planting property.SOLUTION: A seedling transplanter in which a seedling mat placed on a seedling stand is cut out partially at a time with a planting claw 72, to thereby plant seedlings continuously in a field, includes a grooving arm 200 provided near the planting claw 72, and provided so as to be relatively moved to the planting claw 72. The grooving arm 200 has a standby attitude which is a position attitude at a timing for the planting claw 72 to cut out the seedling mat, and a grooving attitude moved forward to the planting claw 72, when planting seedlings to the field, as relative position attitudes to 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 on a field by means of a seedling planting device.

Background Art

[0002] Conventionally, in a seedling transplanter that continuously performs seedling planting work on a field by means of a seedling planting device, while horizontally and vertically feeding a plate-shaped seedling mat placed on a rearwardly inclined seedling placing table, there is a configuration in which a planting claw of the seedling planting device continuously scrapes (cuts) a part of the seedling mat one by one to plant seedlings. In such a seedling transplanter, there is one provided with a grooving arm for making holes for transplantation in a multi-film and digging (grooving) transplantation holes for planting seedlings in the field when planting seedlings with the planting claws (see, for example, Patent Document 1). The multi-film is a film covered for the purpose of moisturizing and warming the soil, suppressing weeds, etc. in the field.

[0003] Patent Document 1 discloses a configuration in which a seedling holding and hole digging arm, which is a grooving arm, is provided below the planting claw via a swing arm. The seedling holding and hole digging arm has a multi-film hole opening blade at its tip and is provided rotatably with respect to the planting claw by a swing arm. The seedling holding and hole digging arm supports the potted seedling taken out by the planting claw from the bottom surface and moves together with the potted seedling. When the potted seedling reaches the field surface, it rotates backward, opens a hole for transplantation in the multi-film with the multi-film hole opening blade, and digs a transplantation hole in the soil.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the configuration disclosed in Patent Document 1, the furrowing arm (seedling holding and hole digging arm) is provided to the planting claws via a bracket or the like, and rotates to release the bottom of the potted seedling after the potted seedling held together with the planting claws has reached the field surface. With such a configuration, the degree of freedom of the relative position of the furrowing arm with respect to the planting claws is low, making it difficult to respond to changes in seedling planting conditions, such as changes in the spacing between plants, regarding the position of the holes made in the mulch film or the position of the transplanting holes excavated in the soil. Note that the spacing between plants is the distance between seedlings that are planted continuously at a predetermined interval in the front-to-back direction.

[0006] Insufficient response to changes in seedling planting conditions can lead to problems such as decreased seedling planting accuracy, increased torque from furrowing on the soil, and interference of the furrowing arm with the planted seedlings. Contact of the furrowing arm with the planted seedlings can damage the seedlings or worsen their planting posture.

[0007] This invention has been made in view of the above-mentioned problems, and aims to provide a seedling transplanter that can suppress interference of the furrowing arm with the planted seedlings and obtain good planting performance. [Means for solving the problem]

[0008] The seedling transplanter according to the present invention is a seedling transplanter that continuously plants seedlings in a field by cutting out portions of a seedling mat placed on a seedling tray using planting claws, and is provided near the planting claws and is provided to move relative to the planting claws, and the furrowing arm has a relative position and posture to the planting claws, which is the waiting position which is the position which is the position which is which when the planting claws cut out portions of the seedling mat, and a furrowing position which is which is moved forward relative to the planting claws when planting seedlings in the field.

[0009] The seedling transplanter according to the present invention is configured such that the furrowing arm performs a cyclical movement, returning from the furrowing position to the standby position after the planting of seedlings in the field by the planting claws is completed.

[0010] The seedling transplanter according to the present invention is configured such that, in the seedling transplanter, the furrowing arm, when in the furrowing position, has its tip protruding forward of the planting claws and is positioned to enter the field surface prior to the planting claws.

[0011] The seedling transplanter according to the present invention is configured such that the furrowing arm does not interfere with seedlings planted in the field, at least within the operating range where its tip is positioned below the field surface.

[0012] The seedling transplanter according to the present invention is configured such that the furrowing arm changes its position and orientation in conjunction with the movement of the planting claws.

[0013] The seedling transplanter according to the present invention is configured such that the furrowing arm is provided with respect to a rotary case that rotatably supports a planting claw device including the planting claws, and the furrowing arm changes its position and orientation in conjunction with the operation of the planting claws by a cam mechanism including a cam that changes the relative position of the furrowing arm with respect to the planting claws as the planting claw device rotates.

[0014] The seedling transplanter according to the present invention is characterized in that the furrowing arm has a plate-shaped portion at its tip that is straight in a side cross-sectional view, and is positioned so that the plate-shaped portion stands upright relative to the field surface when it enters the field surface.

[0015] In the seedling transplanter according to the present invention, the furrowing arm is provided such that, as the movement trajectory of its tip, it traces a path that secures space for pushing out the seedling held by the planting claw located at the lowest end.

[0016] In the seedling transplanter according to the present invention, in the seedling transplanter, the furrowing arm has an arm main body portion provided at a position offset to one side in the left - right direction with respect to the planting claws, and an arm tip portion provided at the tip side of the arm main body portion. thing It is as follows.

[0017] In the seedling transplanter according to the present invention, in the seedling transplanter, the arm tip portion is a portion where one end side in the left - right direction is connected to the arm main body portion, and the furrowing arm is provided at a position offset to the other side in the left - right direction with respect to the planting claws, and has an auxiliary arm portion whose one end side is connected to the other end side in the left - right direction of the arm tip portion.

[0018] In the seedling transplanter according to the present invention, in the seedling transplanter, the furrowing arm has an arm main body portion including a portion provided at a position offset to one side in the left - right direction with respect to the planting claws and a portion provided at a position within the range of the width of the planting claws in the left - right direction, and an arm tip portion provided at the tip side of the arm main body portion.

[0019] In the seedling transplanter according to the present invention, in the seedling transplanter, the arm tip portion is a portion that protrudes to both the left and right sides with respect to the arm main body portion.

Effect of the Invention

[0020] According to the present invention, in a seedling transplanter, interference of the furrowing arm with the planted seedlings can be suppressed, and good planting performance can be obtained.

Brief Description of the Drawings

[0021] [Figure 1] It is a left - side view showing the overall configuration of the seedling transplanter according to the first embodiment of the present invention. [Figure 2] It is a plan view showing the overall configuration of the seedling transplanter according to the first embodiment of the present invention. [Figure 3] It is a diagram showing the power transmission configuration of the seedling transplanter according to the first embodiment of the present invention. [Figure 4]It is a rear perspective view showing the configuration of the seedling transplanter according to the first embodiment of the present invention. [Figure 5] It is a rear view showing the configuration of the seedling transplanter according to the first embodiment of the present invention. [Figure 6] It is a front perspective view showing the configuration of the seedling planting device according to the first embodiment of the present invention. [Figure 7] It is a rear perspective view showing the configuration of the lower part of the seedling transplanter according to the first embodiment of the present invention. [Figure 8] It is a perspective view showing the seedling mat according to the embodiment of the present invention. [Figure 9] It is a plan view showing the seedling mat according to the embodiment of the present invention. [Figure 10] It is a side view showing the seedling mat according to the embodiment of the present invention. [Figure 11] It is a perspective view showing the configuration of the guide rail and the planting claw device according to the first embodiment of the present invention. [Figure 12] It is a left side view showing the configuration of the guide rail and the planting claw device according to the first embodiment of the present invention. [Figure 13] It is a plan view showing the configuration of the guide rail and the planting claw device according to the first embodiment of the present invention. [Figure 14] It is a left side view showing the configuration of the guide rail according to the first embodiment of the present invention and the support configuration of the seedling mat with respect to the guide rail. [Figure 15] It is an explanatory view of the scraping operation of the seedling mat among the operations of the planting claw device according to the first embodiment of the present invention. [Figure 16] It is an explanatory view of the planting operation of the seedling block among the operations of the planting claw device according to the first embodiment of the present invention. [Figure 17] It is a perspective view showing an example of the planting unit according to the first embodiment of the present invention. [Figure 18] It is a left side view showing the planting claw device, the furrowing arm in the furrowing posture, and the link mechanism according to the first embodiment of the present invention. [Figure 19] It is a plan view showing an example of the planting unit according to the first embodiment of the present invention. [Figure 20] This is a left side view showing a planting claw device, a furrowing arm in a standby position, and a link mechanism according to the first embodiment of the present invention. [Figure 21] This is a perspective view showing a groove-making arm according to the first embodiment of the present invention. [Figure 22] This is a left side cross-sectional view showing a part of the groove-making arm according to the first embodiment of the present invention. [Figure 23] This is a diagram showing a cam plate according to the first embodiment of the present invention. [Figure 24] This is an explanatory diagram illustrating the operation of the furrowing arm in accordance with the relative rotation of the planting claw device with respect to the rotary case according to the first embodiment of the present invention. [Figure 25] This is an explanatory diagram illustrating the operation of the furrowing arm in accordance with the relative rotation of the planting claw device with respect to the rotary case according to the first embodiment of the present invention. [Figure 26] This is an explanatory diagram illustrating the operation of the furrowing arm in accordance with the relative rotation of the planting claw device with respect to the rotary case according to the first embodiment of the present invention. [Figure 27] This is an explanatory diagram illustrating the operation of the furrowing arm in accordance with the relative rotation of the planting claw device with respect to the rotary case according to the first embodiment of the present invention. [Figure 28] This is an explanatory diagram illustrating the operation of the furrowing arm in accordance with the relative rotation of the planting claw device with respect to the rotary case according to the first embodiment of the present invention. [Figure 29] This figure shows a graph illustrating the operation of the planting claw device and furrowing arm according to the first embodiment of the present invention. [Figure 30] This is an explanatory diagram illustrating the operation of the planting unit according to the first embodiment of the present invention. [Figure 31] This is an explanatory diagram illustrating the operation of the planting unit according to the first embodiment of the present invention. [Figure 32] This is an explanatory diagram illustrating the operation of the planting unit according to the first embodiment of the present invention. [Figure 33] This is an explanatory diagram illustrating the operation of the planting unit according to the first embodiment of the present invention. [Figure 34]This is an explanatory diagram illustrating the operation of the planting unit according to the first embodiment of the present invention. [Figure 35] This is an explanatory diagram illustrating the operation of the planting unit according to the first embodiment of the present invention. [Figure 36] This is a left side view showing a planting claw device, a furrowing arm in a furrowing position, and a link mechanism according to the first embodiment of the present invention. [Figure 37] This is a left side view showing a planting claw device, a furrowing arm in a standby position, and a link mechanism according to the first embodiment of the present invention. [Figure 38] This is an explanatory diagram of the operation mode of the groove-making arm according to the first embodiment of the present invention. [Figure 39] This figure shows an example of the movement trajectory of the planting claw and furrowing arm according to the first embodiment of the present invention. [Figure 40] This figure shows an example of the movement trajectory of the planting claw and furrowing arm according to the first embodiment of the present invention. [Figure 41] This figure shows an example of the movement trajectory of the planting claw and furrowing arm according to the first embodiment of the present invention. [Figure 42] This is a left side view showing a planting claw device, a furrowing arm in a furrowing position, and a link mechanism according to a second embodiment of the present invention. [Figure 43] This is a plan view showing an example of a planting unit according to a second embodiment of the present invention. [Figure 44] This is a left side view showing a planting claw device, a furrowing arm in a standby position, and a link mechanism according to a second embodiment of the present invention. [Figure 45] This is a perspective view showing a groove-making arm according to a second embodiment of the present invention. [Figure 46] This is a left side cross-sectional view showing a part of the groove-making arm according to the second embodiment of the present invention. [Figure 47] This figure shows an example of the movement trajectory of the planting claw and furrowing arm according to the third embodiment of the present invention. [Figure 48] This is a left side view showing the configuration of a planting claw device according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0022] The present invention aims to achieve good planting performance by planting claws by improving the configuration of a furrowing arm for forming furrows in the field when planting seedlings with planting claws. Embodiments of the present invention will be described below.

[0023] [First Embodiment] The overall configuration of the seedling transplanter 1 according to the first embodiment will be explained using Figures 1 to 7. In the following explanation, the left side (lower side in Figure 2) and the right side (upper side in Figure 2) of the seedling transplanter 1, when viewed from the front, will be referred to as the left and right sides of the seedling transplanter 1, respectively.

[0024] As shown in Figures 1 and 2, the seedling transplanter 1 according to this embodiment is a ride-on type seedling transplanter that carries an operator on board and performs seedling planting work while moving. It is used, for example, to sequentially transplant seedlings of vegetables such as cabbage, onions, and tomatoes into a field. The seedling transplanter 1 comprises a traveling body 2 which constitutes the traveling section and a seedling transplanting device 3 which constitutes the planting section. The seedling transplanting device 3 is connected to the rear of the traveling body 2 so as to be able to move up and down via a linkage device 4 which includes a plurality of links. The seedling transplanting device 3 moves up and down relative to the traveling body 2 by the operation of a hydraulic cylinder (not shown).

[0025] The vehicle body 2 has a vehicle frame 5, left and right front wheels 6, and left and right rear wheels 7. The vehicle frame 5 is constructed in a framework shape by multiple frame members and has a front frame section 11 that constitutes a horizontal frame portion, and a rear frame section 12 that forms a stepped portion that rises one step in a step shape behind the front frame section 11. The left and right front wheels 6 are located below the front frame section 11, and the left and right rear wheels 7 are located below the rear of the rear frame section 12. The vehicle frame 5 is supported by the left and right front wheels 6 and left and right rear wheels 7 in the field.

[0026] In the mobile unit 2, a horizontal floor section 13, made of a body cover or the like, is provided above the front frame section 11. An operating unit 8 for driving and operating the mobile unit 2 and the seedling transplanting device 3 is provided on the floor section 13. A seat support base 9, which is a seat mount, is provided in the left and right center of the rear, 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.

[0027] At the front of the floor 13, there is an operating section 14 that is operated by an operator seated in the seat 10. The operating section 14 includes a dashboard 16 with a steering wheel 15 located in front of the seat 10, various operating pedals such as a gear shift pedal 18, and various operating levers such as a gear shift lever and a clutch lever. The steering wheel 15 is attached to the upper end of a steering shaft 15a that protrudes upward from the dashboard 16.

[0028] An engine 20, which serves as a drive source, is provided in the left-right center of the front of the floor section 13, and in front of and below the steering wheel 15 (see Figure 1). The engine 20 is covered by a bonnet 17. The engine 20 is mounted on an engine support frame section 21 provided on the lower front side of the front frame section 11 via brackets, vibration-damping rubber, etc. (see Figure 1). The engine support frame section 21 includes two support frames 21a, front and rear, which form a U-shape when viewed from the front. The engine 20 is, for example, a diesel engine, and is oriented so that the axial direction of the output shaft is in the left-right direction.

[0029] Behind the engine 20 is a transmission case 22 that houses a power transmission mechanism consisting of gears, a clutch, brakes, and other components. On the left side of the transmission case 22 is an HST23, which is an example of a continuously variable transmission.

[0030] As shown in Figure 3, the power of the engine 20 is transmitted from the output shaft 20a of the engine 20 to the input shaft 23a of the HST 23 via a belt transmission mechanism 24 consisting of pulleys and a belt. The power transmitted to the input shaft 23a is then input from the HST 23 to the power transmission mechanism in the transmission case 22. Here, "HST" refers to a hydraulic continuously variable transmission that employs a method of converting hydraulic pressure generated by driving a hydraulic pump back into rotational force using a hydraulic motor.

[0031] Front axle cases 25 are attached to both the left and right sides of the transmission case 22. The 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 from the front axle case 25 to the left and right. Inside the front axle case 25, there is a power transmission mechanism that transmits the rotational power of the front wheel drive shafts extending from the transmission case 22 to the front axle 26.

[0032] A rear axle case 28 is provided behind the transmission case 22. The rear axle case 28 receives power from the transmission case 22 via a transmission shaft 27 that extends 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 rotates the transmission shaft 27.

[0033] The rear axle case 28 has protruding case portions 28a on both the left and right sides that project rearward from the main case portion. The rear axle 29 is rotatably supported by the left and right case portions 28a, and the rear wheels 7 are attached to the left and right outward extensions of the rear axle 29 from the protruding case portions 28a. A power transmission mechanism is provided inside 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.

[0034] Furthermore, the transmission case 22 has a PTO output shaft 31, which is a power take-off shaft, extending to the rear from its rear end. The power transmission mechanism inside the transmission case 22, which receives power input from the HST 23, rotates the PTO output shaft 31.

[0035] The rotational power of the PTO output shaft 31 is transmitted to the input shaft 34 of the inter-plant speed control case 33 via the PTO transmission shaft 32. The PTO transmission shaft 32 is connected to both the PTO output shaft 31 and the input shaft 34 by universal joints or the like. Inside the inter-plant speed control case 33 is a speed control device 36 consisting of speed-increasing and decreasing gears and a speed control mechanism. The power transmitted to the input shaft 34 is speed-changed by the speed control device 36 inside the inter-plant speed control case 33 and transmitted to the seedling transplanting device 3 by the planting drive shaft 35 that extends rearward from the inter-plant speed control case 33.

[0036] The seedling transplanting device 3 comprises a planting mission case 40 that incorporates a power transmission mechanism that receives power from a planting drive shaft 35, a seedling platform 42 provided on a planting frame 41 connected to the rear side of the link device 4, and a seedling planting device 43 that is driven by power transmitted from the planting mission case 40. In this embodiment, there is a pair of left and right seedling planting devices 43. Note that there may be one seedling planting device 43 or three or more.

[0037] Multiple seedling mats 100 are placed on the seedling tray 42. The seedling tray 42 has a mounting surface on its front side (rear upper side) that receives the placement of the seedling mats 100, and the mounting surface is provided to be in a downward sloping shape. The seedling transplanter 1 according to this embodiment has a four-row planting configuration and has four seedling tray sections 46 arranged in the left-right direction. In the illustration, a state in which a seedling mat 100 is placed only on the second seedling tray section 46 from the left is shown, but in actual planting work, seedling mats 100 are placed on all seedling tray sections 46.

[0038] Each seedling support section 46 has a base body section 46a made of a plate-shaped member that forms the surface on which the seedling mat 100 is placed, and low wall-shaped guide sections 46b provided along the left and right edges of the base body section 46a. The guide sections 46b are protruding portions on the base body section 46a relative to the surface on which the seedling mat 100 is placed, and are provided along the entire length of the base body section 46a in the extending direction. The seedling support section 42 has a vertical feeding structure on the base body section 46a of each seedling support section 46 that intermittently moves the set seedling mat 100 vertically (downward).

[0039] Each seedling tray 46 is provided with a delivery belt 47. In this embodiment, each seedling tray 46 is provided with two rows of delivery belts 47 arranged side by side. The delivery belt 47 is an endless belt whose delivery direction is along the vertical direction when viewed from the rear, and is provided so as to form the lower part of the tray body 46a. The delivery belt 47 is configured to circumferentially drive to move the side that receives the placement of the seedling mat 100 downwards, thereby intermittently feeding the seedling mat 100 vertically.

[0040] A guide rail 48 is provided on the underside of the seedling tray 42, extending linearly in the left-right direction of the machine. The guide rail 48 is provided along the lower edge of the seedling tray 42 and has dimensions longer than the left-right width of the seedling tray 42. In the seedling transplanting device 3, the guide rail 48 is supported and fixed to the planting frame 41 by a predetermined support member. The guide rail 48 supports the seedling mat 100 placed on the seedling tray 42 from below.

[0041] The seedling tray 42 supplies seedling mats 100 placed on each seedling tray section 46 to each planting unit. The seedling tray 42 is configured to reciprocate in the left-right direction (vehicle width direction) by a drive mechanism (not shown) in order to move the seedling mats 100 laterally in the left-right direction (vehicle width direction). In other words, the seedling tray 42 is provided to reciprocate in the left-right direction of the machine with respect to the guide rail 48. Furthermore, when the seedling tray 42 reaches the end of its left-right reciprocating movement, the feed belt 47 is used to vertically feed the seedling mats 100 on each seedling tray section 46 downwards. During the left-right movement of the seedling tray 42, the seedling mats 100 placed on the seedling tray 42 move along the guide rail 48 while being supported from below by the guide rail 48.

[0042] Below the seedling tray 42, a horizontal frame 45 is provided, which forms part of the planting frame 41. The horizontal frame 45 is a linear frame member with a rectangular cylindrical outer shape, and is installed horizontally to extend in the left-right direction. The horizontal frame 45 is provided over substantially the entire left-right range of the seedling transplanting device 3.

[0043] A planting mission case 40 is provided in the center of the horizontal frame 45. The planting mission case 40 is provided in an overhanging manner so that its rear end 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 left-right center of the seedling transplanting device 3.

[0044] 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 planting claw devices 50 provided for each rotary case 52. In other words, the seedling transplanting device 3 has four planting claw devices 50 and corresponds to a four-row planting configuration. On both the left and right sides of the planting transmission case 51, the rotary cases 52 and planting claw devices 50 constitute a planting unit.

[0045] The planting transmission case 51 has a cylindrical outer shape with its longitudinal direction in the front-to-back direction, and its front end is fixed to the rear wall of the horizontal frame 45, extending from the rear side of the horizontal frame 45 toward the rear. A planting transmission shaft 55 is provided between the left and right planting transmission cases 51, with its axial direction in the left-to-right direction.

[0046] The planting transmission shaft 55 is a shaft formed by coaxially connecting multiple shaft bodies with couplings or the like, and is rotatably supported relative to the planting transmission case 40. The planting transmission shaft 55 extends from the rear of the planting transmission case 40 to both the left and right sides, and is rotatably supported relative to each planting transmission case 51 at the front of the left and right planting transmission cases 51. The planting transmission shaft 55 receives power transmission from a power transmission mechanism provided inside the planting transmission case 40. The planting transmission shaft 55 interlocks and connects the power transmission mechanisms within each case of the planting transmission case 40 and the left and right planting transmission cases 51.

[0047] A pair of left and right rotary cases 52 are provided on both the left and right sides of the rear of the planting transmission case 51. The rotary cases 52 are rotatably mounted 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 cases 52 have an elongated outer shape, and their longitudinal center is pivotally supported by the planting transmission case 51. Planting claw devices 50 are attached to the left and right outer sides of the rotary cases 52.

[0048] The planting claw device 50 is rotatably supported on one end of the rotary case 52 in the longitudinal direction, around a rotation axis 50a with the left-right direction as the axis of rotation (see Figure 3). The planting claw device 50 is connected to the rotary case 52 so as to be linked to the rotational movement 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 picks up parts (one seedling at a time) of the seedling mat 100 placed on the seedling tray 42 and plants them in the field. As the seedling transplanter 1 moves forward, one planting claw device 50 plants one row of seedlings.

[0049] The guide rail 48 is provided with an opening 49 that positions the portion of the seedling mat 100 to be scraped and secures the movement path for the planting claw device 50 (see Figure 13). The openings 49 are provided in the longitudinal direction of the guide rail 48 at positions corresponding to each planting claw device 50. Therefore, there are four openings 49 on the guide rail 48. The opening 49 is a notched portion that is open at the rear and follows a rectangular shape in plan view.

[0050] The seedling transplanting device 3, having the configuration described above, receives power input from the planting drive shaft 35 in the planting mission case 40. The driving force input to the planting mission case 40 is transmitted to the planting transmission shaft 55 by a power transmission mechanism within the planting mission case 40. The rotational driving force 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 and gears provided within the planting transmission case 51. The rotational drive of the drive shafts 52a causes the left and right rotary cases 52 to rotate, enabling the planting unit to continuously plant seedlings.

[0051] 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 according to the amount of operation of the gear shifting member, such as the gear shift pedal 18, provided in the driver's unit 8, along with the travel speed of the traveling machine 2. Therefore, the rotational speed of the rotary case 52, that is, the planting speed of the seedling transplanter 3, changes according to the travel speed of the traveling machine 2. Specifically, the faster the machine's travel speed, the shorter the rotation period of the rotary case 52 becomes, and the slower the machine's travel speed, the longer the rotation period of the rotary case 52 becomes. As a result, the planting interval (spacing between plants) of the seedlings remains constant regardless of the travel speed of the traveling machine 2.

[0052] Furthermore, regarding the spacing between plants, as shown in Figure 3, the rotational speed of the rotary case 52 can be changed by the transmission 36 in the plant spacing speed change case 33, thereby changing the plant spacing. The plant spacing is changed according to, for example, the type of crop to be planted or the condition of the field. A planting clutch 37 is provided in the plant spacing speed change case 33. By operating the planting clutch 37, the rotational power from the transmission 36 to the planting drive shaft 35 is intermittently switched. The switching operation of the planting clutch 37 between connection and disconnection is operated by the planting clutch lever provided in the driver's unit 8. The operation of the planting clutch 37 can also be controlled by the controller provided in the seedling transplanter 1.

[0053] Behind each of the four planting units of the seedling transplanting device 3, a pair of soil covering rings 61 are provided. The soil covering rings 61 have a frustoconical shape and are rotatably supported with their outer circumferential surfaces acting on the field. The pair of soil covering rings 61 are positioned with their bottom surfaces facing each other, and are inclined so that the lower side of the outer circumferential surface of each soil covering ring 61 is approximately horizontal, so that they form approximately a "V" shape when viewed from the rear.

[0054] The covering ring 61 is supported via a support member to the rear edge 62a of the covering ring support frame 62, which is configured in a frame shape to surround the seedling planting device 43 in a plan view. The covering ring support frame 62 is installed with its front end supported by the horizontal frame 45. The pair of covering rings 61 compact the soil immediately after planting in the area where seedlings have been planted by the planting claw device 50.

[0055] Furthermore, in the seedling transplanting device 3, stands 64 are provided 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 stand 64 is made up of a pipe-shaped member bent into a roughly "L" shape, and one end is supported by the horizontal frame 45 via a support fitting or the like so that it can rotate axially in the front-to-back direction. The stand 64 moves from a roughly horizontal storage state to an upright state with one side lying along the ground, thereby becoming the usable state that supports the seedling transplanting device 3 relative to the ground. Note that the illustration shows the stand 64 in the storage state, while the stand 64 in the usable state is shown by a dashed line in Figure 5.

[0056] The seedling mat 100 will be described with reference to Figures 8 to 10. The seedling mat 100 is made by sowing multiple 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 rice seeds. When planting seedlings with the seedling transplanter 1, the seedling mat 100 is used in a state where the seedlings have grown from seeds.

[0057] As shown in Figures 8 to 10, the seedling mat 100 has a roughly rectangular plate-like outer shape and is formed as a flat plate overall. In the seedling mat 100, the longitudinal direction (up and down direction in Figure 9) of the rectangular outer shape in plan view is defined as the vertical direction, and the transverse direction (left and right direction in Figure 9) of the same outer shape is defined as the horizontal direction. The vertical and horizontal directions are mutually orthogonal directions in a plan view of the seedling mat 100.

[0058] The seedling mat 100 has a surface portion 101 on one side and a back portion 102 on the other side. The seedling mat 100 has a plurality of surface groove portions 103 formed along the transverse direction at predetermined intervals in the longitudinal direction on the surface portion 101. The seedling mat 100 has side portions 100a, which are the transverse surfaces on both sides, and end portions 100b, which are the longitudinal surfaces on both sides.

[0059] The surface groove portion 103 is a V-shaped groove, 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 surface groove portion 103 is formed so that its depth D1 is, for example, about 1 / 3 to 1 / 2 of the thickness T1 of the seedling mat 100. The seedling mat 100 has an outer shape that is approximately constant throughout the lateral direction when viewed from the side, and both ends of the surface groove portion 103 are open to the side portion 100a of the seedling mat 100.

[0060] In the seedling mat 100, the portion demarcated by the surface groove portion 103 on the surface portion 101 side becomes the row block portion 104. On the surface portion 101 side, the row block portion 104 has relatively protruding ridges formed by the surface groove portions 103 on both sides in the vertical direction. Multiple sowing holes 105 are formed in the row block portion 104 on the surface portion 101 side.

[0061] In the examples shown in Figures 8 to 10, the seedling mat 100 consists of 20 rows of horizontally aligned row blocks 104 connected vertically. In Figure 10, the boundary between adjacent row blocks 104 is indicated by a dashed line B1.

[0062] In each row block section 104, multiple seeding holes 105 are arranged in a single row along the horizontal direction at predetermined intervals. The seeding holes 105 are, for example, roughly cylindrical in shape. One or more seeds are placed in the seeding holes 105. Each row block section 104 has an upper surface 104a that aligns with a virtual plane A1. The seeding holes 105 open facing the upper surface 104a of the row block section 104.

[0063] The seedlings 106 that grow from the seeds in the sowing holes 105 extend out of the sowing holes 105 and extend from the surface portion 101. The seedling mat 100 is made of a material that allows roots to grow from the seeds in the sowing holes 105 on the underside portion 102. The material forming the seedling mat 100 includes organic fiber materials, which are fibrous materials composed of organic matter. Examples of organic fiber materials include coco peat, peat moss, and rice hulls. The material forming the seedling mat 100 may also include a binder, soil conditioner, fertilizer, and soil. Note that the seedlings 106 are not shown in Figures 8 and 9.

[0064] In the seedling mat 100, the area where one sowing hole 105 is formed becomes a unit block portion 108 for one plant, which is scraped (cut) in one go 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 its center when viewed from above, and is scraped from the entire thickness of the seedling mat 100 by the planting claw device 50, separating it from the seedling mat 100 and becoming a roughly rectangular or roughly cubic seedling block 110 (see Figure 15C). This is just one example, but the seedling block 110 has a roughly cubic shape with a side length of about 30 mm.

[0065] In the examples shown in Figures 8 to 10, 10 seeding holes 105 are formed horizontally in each row block section 104, and each row block section 104 is a connected section of 10 unit block sections 108 that become seedling blocks 110 when scraped off by the planting claw device 50. In Figures 8 and 9, the boundary between adjacent unit block sections 108 in a row block section 104 located at the edge of the seedling mat 100 is indicated by a dashed line B2.

[0066] Furthermore, the seedling mat 100 has a plurality of back-side grooves 107 formed on its back surface 102 at predetermined intervals in the vertical direction and along the horizontal direction. The back-side grooves 107 are formed in positions corresponding to the front-side grooves 103 in the vertical direction. Therefore, together with the front-side grooves 103, the back-side grooves 107 shorten the thickness of the seedling mat 100 (vertical direction in Figure 10) at the connection points between adjacent row block sections 104 in the vertical direction.

[0067] The back side groove section 107 is a U-shaped groove, formed by a pair of U-shaped sides and a curved upper curved surface when viewed from the side of the seedling mat 100. The back side groove section 107 is formed so that its depth D2 is, for example, about 1 / 4 to 1 / 3 of the thickness T1 of the seedling mat 100. The back side groove section 107 is open at both ends to the side surface 100a of the seedling mat 100. Note that the shape of the back side groove section 107 is not limited to a U-shape.

[0068] Multiple row block sections 104 are partitioned on the back surface 102 side of the seedling mat 100 by multiple back surface grooves 107 at the same pitch as on the front surface 101 side. On the back surface 102 side, the row block sections 104 form relatively protruding ridges due to the back surface grooves 107 on both sides in the vertical direction. Each row block section 104 has a lower surface 104b that is aligned with a virtual plane A2 parallel to a virtual plane A1.

[0069] The back groove portion 107 is the part of the seedling mat 100 placed on the delivery belt 47 that receives the engagement of a plurality of locking protrusions 47a (see Figure 7) provided on the delivery belt 47. The protrusions 47a are parts that protrude from the surface of the delivery belt 47 and are formed in a straight line along the left-right direction. The protrusions 47a have a cross-sectional shape that follows, for example, a rectangular shape. The vertical spacing of the plurality of protrusions 47a corresponds to the vertical spacing of the plurality of back groove portions 107 on the seedling mat 100. The back groove portion 107 is formed to be slightly wider than the protrusions 47a in order to accommodate the protrusions 47a.

[0070] When the seedling mat 100 is placed on the delivery belt 47, the protruding portions 47a are fitted into each of the grooves 107 on the back surface, thereby securing it to the delivery belt 47. As a result, the seedling mat 100 can reliably receive the vertical feeding action of the delivery belt 47 without slipping against the delivery belt 47, which is driven circulating as a vertical feeding operation. In other words, the seedling tray 42 can reliably feed the seedling mat 100 vertically toward the guide rail 48 by the delivery belt 47. Furthermore, the securing action of the seedling mat 100 to the delivery belt 47 by fitting the protruding portions 47a into each of the grooves 107 on the back surface prevents the seedling mat 100 from being compressed vertically by its own weight.

[0071] 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: Starting from the unit block section 108 located at the starting end, which is one end on the left or right of the lower row block section 104 that is supported by the guide rail 48, the mat is sequentially scraped off towards the other side as the seedling platform 42 moves to one side. In other words, in the cycle of one scraping by the planting claw device 50, the seedling mat 100 moves along the guide rail 48 by the distance of one unit block section 108 in the lateral direction, and a new unit block section 108 is sequentially positioned on the opening section 49, which is the position to be scraped.

[0072] The row block sections 104 at the lower end are sequentially scraped away from the starting end, and when the unit block sections 108 at the end of the row block section 104 on the left and right sides are scraped away, the feed belt 47 moves the seedling mat 100 down by one row of the row block section 104 (vertically feeds it), and the seedling mat 100 is supported by the guide rail 48 from the end face 100b side of the row block section 104 which is now located at the lower end. In other words, a new row block section 104 is positioned on the guide rail 48 as the part to be scraped. Then, the seedling mat 100 moves as the seedling tray 42, which was previously the end end, moves back to the left and right sides, and the unit block sections 108 are sequentially scraped away.

[0073] In this way, the seedling mat 100 is scraped off unit block sections 108 by the planting claw device 50, which rotates in a predetermined trajectory, moving back and forth from bottom to top, through lateral movement by the left-right reciprocating movement of the seedling tray 42 and vertical movement by the intermittent operation of the delivery belt 47.

[0074] In the seedling mat 100, the end face portion 100b on the side 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 groove portion 107 on the back side, and an intermediate surface 109a between the groove-forming surface 103a and the groove-forming surface 107a. Since the seedling mat 100 has a periodic shape in the vertical direction with row block portions 104 as units, the shape of the end face portion 100b is approximately the same for the lower end face portion 100b of the seedling mat 100 before being scraped by the planting claw device 50 and for the end face portion 100b of the seedling mat 100 after at least one row of row block portions 104 has been scraped. In the end face portion 100b after being scraped by the planting claw device 50, the intermediate surface 109a becomes the cut surface of the planting claw device 50.

[0075] Thus, 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 side opposite to the mounting surface of the seedling tray 42, and which corresponds to the cutting unit by the planting claws 72 and extends in a direction perpendicular to the longitudinal feeding direction.

[0076] The configuration of the planting claw device 50 will be explained using Figures 6 and 11 to 13. For the sake of clarity, 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 includes an arm portion 71, a planting claw 72 fixed to the arm portion 71, an extrusion member 73 movably provided relative to the arm portion 71, a retaining plate 74 as a holding member provided opposite the planting claw 72, a retaining plate support portion 75 supporting the retaining plate 74, and an excavating claw 76 provided below the retaining plate 74.

[0077] The planting claw device 50 has a base 70 at the connection point to the rotary case 52, and an extension portion that extends linearly from the base 70 in a predetermined direction, with the tip of the planting claw 72 being the tip of the extension portion. Hereafter, the direction along the extension direction of the extension portion in the planting claw device 50 (the direction of arrow C1 in Figure 12) will be referred to as the "claw extension direction". 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 as the rear side.

[0078] The arm portion 71 is a substantially cylindrical part of the planting claw device 50 with the claw extension direction oriented along the cylindrical axis. The arm portion 71 extends from the base portion 70 in the claw extension direction as an integral part of the base portion 70.

[0079] The planting claw 72 has a roughly rectangular plate-shaped claw base 81 and two claw body portions 82 extending in the claw extension direction from one side in the longitudinal direction of the claw base 81, with a bifurcated tip. The planting claw 72 has a roughly constant width overall, with the width direction being the left-right direction and the longitudinal direction being aligned with the claw extension direction.

[0080] The claw base 81 is a bent plate-like portion with a flattened, roughly "U" shaped cross-section, and has a flat portion and side wall portions on both the left and right sides. The claw body portion 82 extends from the upper side of the front end of the claw base 81 in the direction of claw extension.

[0081] The planting claw 72 is fixed to the upper side of the arm portion 71 by two fixing portions provided at intervals in the direction of claw extension on the claw base portion 81. The fixing portions of the planting claw 72 are fastening and fixing portions in which a nut 84 is screwed onto a male screw portion 83 that protrudes upward from the arm portion 71 and penetrates the flat portion of the claw base portion 81.

[0082] The pair of claw body portions 82 extend linearly from both widthwise edges of the claw base portion 81 along the claw extension direction. The pair of claw body portions 82 are formed parallel to each other with a gap of approximately constant width between them, and a space portion 85 is formed between the pair of claw body portions 82.

[0083] Each claw body portion 82 has a pointed tip portion 82a formed to be sharp. A pair of claw body portions 82 have a shape that is approximately symmetrical in the left-right direction. Each claw body portion 82 has a roughly "L" shaped cross-section due to its top surface portion 82b and left and right outer side portions 82c. The distance between the side portions 82c of the left and right claw body portions 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 portions 82c.

[0084] The extrusion member 73 is provided on the front side of the arm portion 71 and is configured to reciprocate along the claw extension direction relative to the arm portion 71. The extrusion member 73 is provided on the underside of the pair of claw body portions 82 of the planting claw 72. The extrusion member 73 has a push rod 86 and a pressing piece 87 provided on the tip side of the push rod 86.

[0085] The push rod 86 is a rod portion that, together with the arm portion 71, constitutes a cylinder mechanism, with the arm portion 71 acting as the cylinder portion, and extends from the tip of the arm portion 71 along the direction of claw extension. The push rod 86 reciprocates relative to the arm portion 71 to change the amount of protrusion from the arm portion 71. The tip of the push rod 86 is a bent portion 86a, which is bent at a right angle upward relative to the rod body.

[0086] 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 shape that is roughly "U" in the axial view of the push rod 86, corresponding to the shapes of the support plate portion 87a and the left and right side wall portions 87b, with a notch portion 87d (see Figure 13) that is open on the upper side.

[0087] 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 95 is formed between the left and right side wall portions 87b on the support plate portion 87a, with the front side open by a notch portion 87d. The pressing piece 87 moves integrally with the push rod 86 relative to the arm portion 71.

[0088] 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 shape in which the vertical dimension of the front portion is larger than that of the rear portion at the side wall portion 87b. 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 body portion 82 and are positioned inside the claw body portion 82, which has a roughly "L" shaped cross-section.

[0089] The extrusion member 73 moves back and forth between a holding position, which is the rear end position (see Figure 16A), and an extrusion position, which is the front end position (see Figure 16B), in relation to its movement relative to the arm portion 71.

[0090] The holding position of the extrusion member 73 is the standby position of the extrusion member 73 in the planting claw device 50, which is the position when the planting claw device 50 is holding the seedling block 110. When the extrusion member 73 is in the holding position, the pressing piece 87 is located in the middle of the claw body portion 82 in the claw extension direction.

[0091] 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 when the planting claw device 50 has pushed out (released) the seedling block 110. With the extrusion member 73 in the extrusion position, the pressing piece 87 positions its front end in the claw extension direction at approximately the same position as the sharpened portion 82a of the claw body portion 82.

[0092] The retaining plate 74 is a plate-shaped member having a predetermined bent shape when viewed from the side, and is capable of elastic deformation. The retaining plate 74 is oriented with its width direction to the left-right direction, and extends from the lower side of the arm portion 71, opposite to the fixed side of the planting claw 72, toward the direction of claw extension. The retaining plate 74 is provided on the lower side of the pair of claw body portions 82, facing the claw body portions 82. The retaining plate 74 is formed of, for example, sheet metal with a thickness of several millimeters.

[0093] The retaining plate 74 has a bent shape when viewed from the side, and from the rear side (arm portion 71 side) to the front side (tip side of the claw body portion 82), it has a base plate portion 74a, an inclined plate portion 74b, and a tip bent portion 74c in that order. The tip of the retaining plate 74 is positioned to approximately coincide with the tip of the claw body portion 82 in the direction of claw protrusion.

[0094] The base plate portion 74a is the part that extends along the direction of claw extension and is parallel to the claw body portion 82. The base plate portion 74a makes up approximately half of the longitudinal direction of the retaining plate 74. The inclined plate portion 74b is the part that is bent at an obtuse angle with respect to the base plate portion 74a. In a side view, the angle between the base plate portion 74a and the inclined plate portion 74b is, for example, about 140°. The retaining plate 74 gradually narrows the distance between itself and the claw body portion 82 from the rear to the front due to the inclined plate portion 74b.

[0095] The tip bent portion 74c is a part that is bent at a right angle or obtuse angle to the inclined plate portion 74b. In a side view, the angle between the inclined plate portion 74b and the tip bent portion 74c is, for example, about 100°. The retaining plate 74 gradually widens the distance between itself and the claw body portion 82 from the rear to the front due to the tip bent portion 74c.

[0096] The retaining plate 74 has a convex ridge portion 74d on the upper side (towards the claw body portion 82) formed by an inclined plate portion 74b and a bent tip portion 74c, positioned near the tip of the claw body portion 82. The distance between the left and right claw body portions 82 and the ridge portions 74d of the retaining 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 claw body portion 82 and the ridge portion 74d.

[0097] The retaining plate 74 functions as a leaf spring that holds the seedling block 110, which has been scraped off by the claw body 82, together with the claw body 82. In other words, the retaining plate 74, with its elastic deformation relative to its natural state, widens the gap between itself and the claw body 82, and holds the seedling block 110 together with the pair of claw body 82 with a biasing force. The retaining plate 74 is supported in a fixed state by the retaining plate support 75.

[0098] The retaining plate support portion 75 is made up of a plate-shaped member with the left-right direction as the thickness direction, and is attached to the base portion 70 of the planting claw device 50 on the side opposite to the planting transmission case 51 in the left-right direction. The retaining plate support portion 75 is fastened and fixed to the base portion 70 by bolts 88.

[0099] The retaining plate support portion 75 has its upper edge positioned near the lower part of the arm portion 71. The retaining plate 74 is fixed to the upper edge of the front part of the retaining plate support portion 75. The retaining plate 74 has a fixed surface portion 74e on one side (the planting transmission case 51 side) of the base plate portion 74a, which is bent at a right angle to the base plate portion 74a. The retaining plate 74 is fastened and fixed to the retaining plate support portion 75 at two points, front and rear, by bolts 89 that pass through the excavation claw 76 and the retaining plate support portion 75 and nuts 90 that are screwed onto them, with the fixed surface portion 74e aligned along one side of the retaining plate support portion 75. The retaining plate 74 may also be directly attached to the arm portion 71.

[0100] The digging claws 76 are located below the retaining plate 74 and are positioned in the left-right direction opposite to the planting transmission case 51 side relative to the retaining plate support portion 75. The digging claws 76 have a pair of claw bodies 77 and a connecting portion 78 provided between the pair of claw bodies 77.

[0101] The claw body 77 is a plate-shaped member with the left-right direction as the thickness direction, and extends forward from the retaining plate support portion 75 in the direction of claw extension. In a side view, the claw body 77 has a pointed shape that gradually narrows from the base to the tip. In the direction of claw extension, the rear end of the claw body 77 is positioned at approximately the same position as the rear end of the retaining plate 74, while the tip is positioned forward of the tip of the retaining plate 74.

[0102] The excavation claws 76 are provided with the rear ends of a pair of claw bodies 77 aligned with the underside of the base plate portion 74a of the retaining 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 retaining plate 74. The connecting portion 78 is interposed between the rear ends of the pair of claw bodies 77 and functions as a spacer between the left and right claw bodies 77.

[0103] The excavation claw 76 is provided with its rear end fixed to the retaining plate support portion 75. The excavation claw 76 is fixed to the retaining plate support portion 75 together with the retaining plate 74 by two bolts 89 used to fix the retaining plate 74 to the retaining plate support portion 75. The bolts 89 pass through the pair of claw bodies 77 and the connecting portion 78 interposed between them, as well as through the retaining plate support portion 75 and the fixing surface portion 74e of the retaining plate 74, and are screwed into nuts 90.

[0104] The excavating claws 76 have the function of protecting the holding plate 74 by excavating the field before the holding plate 74 when the seedling block 110 is planted by the planting claw device 50, thereby reducing the contact resistance of the holding plate 74 to the field. In addition, by reaching the field before the holding plate 74, the excavating 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.

[0105] The configuration of the guide rail 48 will be explained using Figures 11 to 14. The guide rail 48 is provided on the underside of the seedling tray 42 and supports the seedling mat 100 by contacting the lower end face portion 100b of the seedling mat 100 placed on the seedling tray 42, thereby defining the position of the seedling mat 100 with respect to the track of the planting claws 72.

[0106] The guide rail 48 is constructed from a plate-shaped member having a predetermined bend shape, so that it has a constant cross-sectional shape that is the same as the shape of both end faces (side view shape) over substantially its entire length. The part of the guide rail 48 that forms the side view shape has, in general terms, a front inclined surface portion 121 that slopes downward to the rear so as to follow the mounting surface of the seedling tray 42, and a rear inclined surface portion 122 that, together with the front inclined surface portion 121, forms a substantially "V" shape in side view, and these surfaces are arranged to form a trough shape.

[0107] The guide rail 48 has a configuration in which a first rail member 123, which forms the front portion in a plan view, and a second rail member 124, which forms 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 121, and the second rail member 124 forms the lower portion of the front inclined surface 121 and the rear inclined surface 122.

[0108] The connecting member 125 is located on the back side of the front inclined surface 121 (opposite the side on which the seedling mat 100 is placed) so as to straddle the joint portion 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 running horizontally, and multiple connecting members are provided in the horizontal direction. The connecting member 125 connects the first rail member 123 and the second rail member 124 by receiving fixing screws 126 that pass through the rear edge of the first rail member 123 and the front edge of the second rail member 124, respectively. The guide rail 48 may be composed of a single rail member.

[0109] The guide rail 48 has notched openings 49 at multiple locations (4 locations) along its longitudinal direction, which position the portion (unit block portion 108) of the seedling mat 100 that will be cut off by the planting claws 72. As shown in Figure 13, the opening 49 is a notched portion with the rear side open, and has left and right side edges 49a that face each other in the left-right direction, and a front edge 49b that runs along the left-right direction. In addition, chamfered portions 49c are formed at the left and right corners of the opening edge of the opening 49, forming inclined edges relative to the side edges 49a. The left and right chamfered portions 49c widen the left and right width of the opening end of the opening 49. The opening 49 is notched in shape over the entire area of ​​the front inclined surface portion 121 and the rear inclined surface portion 122 in the front-rear direction in a plan view.

[0110] As shown in Figure 13, the left and right width dimension G1 of the intake portion 49, that is, the distance between the left and right side edges 49a, is approximately the same as the width dimension G2 of the planting claw 72, which has a predetermined width. In detail, the guide rail 48 has a width dimension G1 of the intake portion 49 that is slightly larger than the width dimension G2 of the planting claw 72. As shown in Figure 13, the planting claw device 50 is installed so that the left and right sides of the planting claw 72 are positioned inward by a predetermined gap G3 relative to the left and right side edges 49a of the intake portion 49 in the left-right direction. The size of the gap G3 is, for example, several millimeters (for example, 3 mm). The planting claw device 50 is configured to perform the 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.

[0111] The guide rail 48 has a contact support surface portion 130 that receives 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 relative to the contact support surface portion 130, creating 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 surface groove portion 103 of the seedling mat 100. The contact support surface portion 130 has an inclined support surface portion 134 as the part that follows the groove forming surface 103a.

[0112] The contact support surface portion 130 is the 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 the rear upper portion of the rear inclined surface portion 122, which is generally an upward sloping surface portion.

[0113] In the contact support surface portion 130, the inclined support surface portion 134 is the part that receives contact with the groove-forming surface 103a of the lower end surface portion 100b of the seedling mat 100 in a set state placed on the seedling tray 42. The inclined support surface portion 134 is inclined 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 a set state, depending on the shape of the surface groove portion 103 of the seedling mat 100.

[0114] The contact support surface portion 130 has an edge end surface portion 135 on the rear side of the inclined support surface portion 134, which forms the rear edge end of the guide rail 48. The contact support surface portion 130 is formed by the inclined support surface portion 134 and the edge end surface portion 135 as a bent surface portion that has an obtuse angle when viewed from the side.

[0115] In the example shown in Figure 14, the inclined support surface 134 is inclined such that the angle θ1 it makes with respect to the direction perpendicular to the inclination direction of the mounting surface of the seedling tray 42 in a side view (see arrow H1, hereinafter referred to as "mounting surface inclination direction") is approximately 30°. However, the inclination angle of the inclined support surface 134 is not limited and can be determined appropriately in accordance with the shape of the surface groove portion 103 of the seedling mat 100, etc.

[0116] In the following, the direction perpendicular to the mounting surface inclination direction in a side view will be referred to as the mounting surface orthogonal direction (see Figure 14, arrow H2). The mounting surface inclination direction corresponds to the longitudinal feeding direction of the seedling mat 100. Furthermore, the longitudinal direction of the set seedling mat 100 corresponds to the mounting surface inclination direction, and the thickness direction of the set seedling mat 100 corresponds to the mounting surface orthogonal direction.

[0117] The groove-forming portion 133 is formed by the front lower portion of the rear inclined surface portion 122 and the rear lower portion of the front inclined surface portion 121. The groove-forming portion 133, as a portion formed by the rear inclined surface portion 122, has a rear groove side portion 136 which is a surface portion that is aligned with the inclination direction of the mounting surface in a side view, and a groove bottom portion 137 which is a surface portion that is aligned with the direction perpendicular to the mounting surface in a side view.

[0118] Furthermore, the groove-forming portion 133 has a front groove side portion 138 that is aligned with the inclination direction of the mounting surface in a side view, as a portion formed by the front inclined surface portion 121. The front groove side portion 138 is the portion on the lower end side of the front inclined surface portion 121 and is the portion that faces the rear groove side portion 136 in the direction perpendicular to the mounting surface. The rear groove side portion 136 and the front groove side portion 138 are portions that are bent at a right angle to the groove bottom surface portion 137 on both sides of the groove bottom surface portion 137 in the direction perpendicular to the mounting surface, with the corners forming curved surfaces (R-shaped portions).

[0119] Thus, the groove-forming section 133, with its rear groove side surface 136, front groove side surface 138, and groove bottom surface 137, forms a roughly U-shaped groove that follows a roughly rectangular shape in a side view, with the seedling mat 100 side in the set state being the open side. The lower side of the inclined support surface 134 is connected to the upper side of the rear groove side surface 136. The rear groove side surface 136 and the inclined support surface 134 form an obtuse-angled bent surface in a side view.

[0120] The upper part of the front groove side portion 138 extends along the direction of the mounting surface inclination in a side view, as the upper part of the front inclined surface portion 121. A support edge portion 139 is provided on the front side of the upper edge of the front inclined surface portion 121, which is bent at a right angle with the corner portion being a curved surface portion.

[0121] As shown in Figure 14, the seedling mat 100, supported by the guide rail 48, is supported with respect to the guide rail 48 such that the groove-forming surface 103a on the end face 100b is in contact with the inner surface 134a of the inclined support surface 134, and the portion below the groove-forming surface 103a (towards the lower surface 104b) faces into the concave groove 131. In other words, the seedling mat 100 is supported by the guide rail 48 with respect to the end face 100b by the groove-forming surface 103a that is in contact with the inclined support surface 134, while the intermediate surface 109a and the groove-forming surface 107a are facing the groove bottom surface 137 via the space 132. The inner surface 134a of the inclined support surface 134 serves as a sliding surface, or guide surface, for the seedling mat 100 as it is moved laterally.

[0122] In the guide rail 48, the edge end surface 135 forming the rear edge is, in a side view, a portion that extends above the upper surface 104a in the direction perpendicular to the mounting surface relative to the seedling mat 100. Also, in the guide rail 48, the surface 121a of the front inclined surface 121 is the surface that receives contact with the lower surface 104b of the lower end row block portion 104. The front inclined surface 121 has a length (width) that includes the entirety of at least one row of row block portion 104 in the direction of the inclination of the mounting surface.

[0123] As described above, the guide rail 48 has a front inclined surface portion 121 with the lower part being the front groove side portion 138, a rear groove side portion 136 and groove bottom portion 137 which together form a concave groove 131 with the front groove side portion 138, and an inclined support surface portion 134 and edge end portion 135 which form a contact support surface portion 130.

[0124] In the guide rail 48, a cutting aid section 140 is provided at the opening end of the concave groove 131 relative to the take-off section 49, which either eliminates the recess of the concave groove 131 or reduces its depth. The cutting aid section 140 is provided on both the left and right sides of each take-off section 49, and the cutting aid sections 140 on both the left and right sides of each take-off section 49 are configured symmetrically in the left-right direction. Note that the cutting aid section 140 is not shown in Figure 14.

[0125] The cutting assistance section 140 is a portion of the recessed groove 131 that is partially raised on both the left and right sides of the opening section 49 by the depth of the recessed groove 131. The cutting assistance section 140 is provided by attaching a cutting assistance member 150 to the opening end of the recessed groove 131 in the guide rail 48 relative to the opening section 49. The cutting assistance member 150 is a roughly rectangular plate-shaped or block-shaped metal member that is fixed to the guide rail 48 while fitted into the recessed groove 131.

[0126] As shown in Figures 11 and 13, the cutting assist member 150 has a rectangular shape in plan view and is oriented so that its longitudinal direction is the direction in which the concave groove 131 extends. The cutting assist member 150 has a first end face 151, which is one end face in the longitudinal direction, and a second end face 152, which is the other end face in the longitudinal direction. The width dimension of the cutting assist member 150 is approximately the same as the width dimension of the concave groove 131, and it is provided in a manner that fits between the rear groove side surface 136 and the front groove side surface 138 of the concave groove 131. The cutting assist member 150 also has a horizontal upper surface 156.

[0127] The cutting support member 150 is fixed to the guide rail 48 by a single screw 161. The screw 161 passes through the groove bottom surface 137 of the concave groove 131 from the underside of the guide rail 48 and is screwed into a screw hole 158 formed in the cutting support member 150. The screw hole 158 is formed to penetrate through the cutting support member 150 in the thickness direction. A hole 137b is formed in the groove bottom surface 137 for the screw 161 to pass through (see Figure 14).

[0128] The cutting assist member 150 is provided with its first end face 151 facing the opening portion 49 of the guide rail 48. The cutting assist member 150 is provided so that its first end face 151 is flush with the end face forming the side edge portion 49a of the opening portion 49.

[0129] As described above, in the configuration in which the cutting assist member 150 is attached to the concave groove 131 of the guide rail 48, the upper surface 156 forms a cutting assist surface that raises the bottom surface 137a of the concave groove 131 by the depth of the groove. In other words, the cutting assist portion 140 is the part of the concave groove 131 where the recess has been eliminated, and in the cutting assist portion 140, the upper surface 156 is formed by the cutting assist member 150 as a raised surface relative to the bottom surface 137a of the concave 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.

[0130] In this embodiment, the cutting assist member 150 has a thickness approximately the same as the depth of the concave groove 131, and in the area of ​​the concave groove 131 where the cutting assist member 150 is installed, the cutting assist member 150 fills approximately the entire depth of the concave groove 131. In other words, in the area where the cutting assist member 150 is installed, the opening end of the concave groove 131 is closed by the cutting assist member 150, and the concave groove 131 is eliminated. Note that the cutting assist portion 140 may be provided as a shaped part of the guide rail 48 itself, rather than being configured by attaching the cutting assist member 150 to the guide rail 48.

[0131] The operation of the planting claw device 50, which has the above configuration, will be explained using Figures 15 and 16. For the sake of explanation, the furrowing arm 200 and its support mechanism, which will be described later, are not shown in Figures 15 and 16. As shown in Figures 15A to 15C, and Figures 16A and 16B, the planting claw device 50 rotates continuously as the drive shaft 52a of the rotary case 52 (see Figure 6) rotates, repeatedly removing (scraping) seedling blocks 110 from the seedling mat 100 supported on the guide rail 48, transporting the seedling blocks 110 while temporarily holding them, and planting the seedling blocks 110.

[0132] Figure 15A shows the state immediately before the planting claw device 50 scrapes the seedling mat 100. As shown in Figure 15A, the planting claw device 50 brings its claw body 82 closer to the guide rail 48 that supports the seedling mat 100 from below, from the upper rear side. The planting claw device 50 targets one unit block 108 of the row block 104 at the lower end of the seedling mat 100 supported by the guide rail 48, and brings its claw body 82 closer to that unit block 108. The unit block 108 to be scraped is located on the opening 49 of the guide rail 48.

[0133] As shown in Figure 15B, the planting claw device 50 inserts the tip of the claw body 82 into the upper surface groove 103 of the unit block 108 to be scraped from the seedling mat 100.

[0134] Then, as the planting claw device 50 moves forward and downward in a swinging motion, the unit block portion 108 is scraped off by the planting claws 72, as shown in Figure 15C, and is 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 a pair of claw body portions 82 and a holding plate 74. In scraping off the unit block portion 108, a guiding effect is obtained by the tip bend portion 74c, which widens the gap between the tips of the claw body portion 82 and the holding plate 74. In addition, the unit block portion 108 to be scraped off is guided by the groove shape of the surface side groove portion 103 that receives the tip of the claw body portion 82.

[0135] In removing seedling mats 100, the planting claw device 50 acts on the seedling mats 100 while tracing a predetermined trajectory E1 (see Figure 12) with respect to the guide rail 48, in a side view, for the movement trajectory of the tip of the claw body 82. Trajectory E1 has a curved shape with the upper side convex near the guide rail 48, and forms a loop overall. In a side view, the tip of the claw body 82 passes near the boundary between adjacent row block sections 104 (Figure 10, dashed line B1).

[0136] Furthermore, when scraping the seedling mat 100, since the cutting assist part 140 is provided at the opening end of the guide rail 48 relative to the intake portion 49, good cutting performance (cutting performance) can be obtained. Specifically, the cutting assist part 140 can fill the space 132 of the concave groove 131, which is a space for the seedling mat 100 to escape, on the underside of the seedling mat 100 that is subjected to the action of the planting claws 72 from above, and the seedling mat 100 can be supported from below even at the part where the concave groove 131 is formed, so that the seedling mat 100 does not escape and good shearing action can be obtained. As a result, stable scraping can be performed.

[0137] As shown in Figure 15C, the seedling block 110 scraped off by the planting claws 72 is held between a pair of claw bodies 82 and a 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, in the state in which the seedling block 110 is held, the elastic deformation of the holding plate 74 causes the gap between the pair of claw bodies 82 and the holding plate 74 to widen compared to the state before the seedling block 110 was held.

[0138] A pressing piece 87 is positioned on the rear side of 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 body parts 82 and the space 95 of the pressing piece 87 (see Figure 11) become the space for positioning the seedling 106 of the held seedling block 110, thus preventing interference of the seedling 106 with the planting claw device 50.

[0139] As shown in Figure 16A, the planting claw device 50, while holding the seedling block 110, moves downward while pointing the tip of the planting claw 72 downwards. Then, as shown in Figure 16B, at a predetermined timing when the tip of the planting claw 72 is positioned in the field below the field surface 91, the planting claw device 50 pushes out (releases) the seedling block 110 with the extrusion member 73. The planting claw device 50 moves the extrusion member 73 forward relative to the arm portion 71, thereby pushing out the seedling block 110 in the direction of claw extension (see arrow F1). The seedling block 110 is released with the force of the extrusion by the extrusion member 73 and planted in the field at a predetermined planting depth.

[0140] In the extrusion of the seedling block 110 by the extrusion member 73, the extrusion member 73 applies pressure to the seedling block 110 using the pressing surface 87e of the pressing piece 87 as the contact surface with the seedling block 110. The contact surface of the pressing surface 87e with respect to the seedling block 110 corresponds to the upper surface 104a of the seedling mat 100. The extrusion member 73 also moves forward with a biasing force relative to the arm portion 71, extruding the seedling block 110 in a manner that ejects it. Furthermore, when the seedling block 110 is planted in the field, it is covered from the rear by the holding plate 74, thus protecting it from impact with the field.

[0141] Furthermore, when the planting claw device 50 acts on the field surface 91, it excavates the field surface 91 with the excavating claws 76 before the holding plate 74. This reduces the contact resistance of the holding plate 74 with respect to the field surface 91, protecting the holding plate 74, and also prevents the mulch film from becoming entangled with the holding plate 74.

[0142] The planting claw device 50, having planted seedling blocks 110 in the field, moves upward relative to the field surface 91 while gradually returning the extrusion member 73, which is in the extrusion position, to the holding position. Then, the planting claw device 50 returns to a position where the planting claws 72 are positioned above and behind the guide rail 48, and performs the extrusion and planting of the next unit block section 108 to be extruded. In this way, the planting claw device 50 rotates so as to trace a loop-shaped trajectory E1 with the tip of the claw body 82, extruding one unit block section 108 and planting one seedling block 110 in one cycle, and as the machine moves forward, it continuously plants seedlings in a line at predetermined intervals.

[0143] In the seedling mat 100, the row block section 104 at the lower end, that is, the row block section 104 located on the guide rail 48, is the target of scraping during one stroke of lateral movement of the seedling mat 100 in either the left or right direction. Through continuous planting operations by the planting claw device 50 while the seedling mat 100 is laterally moved to one side, the seedling mat 100 is moved vertically by the delivery belt 47 at a predetermined timing when all the unit block sections 108 of the row block section 104 located at the lower end have been scraped off.

[0144] After the seedling mat 100 has been fed vertically, the row block section 104 located at the lower end is sequentially scraped from the unit block section 108 while the seedling mat 100 is fed horizontally to the left or right. In this way, the seedling mat 100 is fed vertically intermittently while moving back and forth in the left and right directions by the horizontal feeding, and is sequentially scraped from the lower row block section 104 by the planting claw device 50.

[0145] As described above, the seedling transplanter 1 is configured to move the seedling mat 100, which is placed on the seedling tray 42, in a lateral movement direction along the left-right direction of the machine, and intermittently move the seedling mat 100 in a longitudinal movement direction along the front-rear direction of the machine in a plan view, while cutting off parts of the seedling mat 100 with the planting claws 72 to continuously plant seedlings 106 in the field.

[0146] As shown in Figures 6, 17 to 21, the seedling transplanter 1, having the above configuration, is equipped with furrowing arms 200 in the seedling transplanting device 3 for pre-treatment of the field, such as forming furrows in the field or cutting mulch film, when planting seedlings with planting claws 72. The furrowing arms 200 are provided corresponding to each of the four planting claw devices 50, and the seedling transplanter 3 has four furrowing arms 200. The furrowing arms 200 and the link mechanism 300 and cam mechanism 400, described later, provided to the furrowing arms 200 are configured symmetrically with the planting transmission case 51 side 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.

[0147] The furrowing arm 200 is installed attached to the planting claw device 50. The furrowing arm 200 is configured in a longitudinal shape, and is positioned so that its longitudinal direction is aligned with the claw extension direction. The furrowing arm 200 is installed in the vicinity of the planting claws 72 relative to the planting claw device 50.

[0148] The furrowing arm 200 is supported by a link mechanism 300 so as to be movable relative to the planting claw device 50. As a result, the furrowing arm 200 is positioned to move relative to the planting claw 72.

[0149] The furrowing arm 200 is configured to have a roughly "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 body portion 201, an arm tip portion 202, and an auxiliary arm portion 203 as the roughly "U" shaped outer part. These parts constituting the furrowing arm 200 are provided as plate-like portions having a predetermined shape.

[0150] The groove-making arm 200 has a support plate 204 and a cutter member 205 as its constituent components. The support plate 204 and the cutter member 205 are connected and fixed to each other, forming an integrated groove-making arm 200.

[0151] The support plate 204 is a substantially rectangular plate-like member whose longitudinal direction is the extension direction when viewed from the side of the groove-making arm 200, and it forms the support base of the groove-making arm 200. In detail, the support plate 204 has a narrower front portion compared to the rear portion, and in terms of its side view shape (plate surface shape), it has a gently tapering shape from the rear to the front.

[0152] The cutter member 205 is a bent plate-shaped member that forms a roughly "U" shape in plan view and constitutes the main body portion of the groove-making arm 200. The cutter member 205 has an outer surface portion 205a, a front surface portion 205b, and an inner surface portion 205c as a roughly "U" shape surface portion (see Figure 21).

[0153] The arm body 201 is positioned offset to one side in the left-right direction relative to the planting claw 72. Regarding the arrangement of the arm body 201, the side in the left-right direction relative to the planting claw 72 is the side opposite to the planting transmission case 51 in the left-right direction. In the description of the furrowing arm 200, the side of the planting transmission case 51 (upper side in Figure 19) is considered the inside, and the side opposite to the planting transmission case 51 (lower side in Figure 19) is considered the outside. The arm body 201 is a plate-shaped portion with the left-right direction as the plate thickness direction, and is formed by the support plate 204 and the outer surface portion 205a of the cutter member 205.

[0154] The cutter member 205 is fixed to the support plate 204 with its rear end of the outer surface portion 205a overlapping the front end of the support plate 204 from the outside. The outer surface portion 205a has approximately the same width as the front end of the support plate 204 at its rear end and forms a continuous shape with the support plate 204 in the front-to-rear intermediate portion of the arm body portion 201.

[0155] Furthermore, the outer surface portion 205a of the cutter member 205, which forms the front part of the arm body portion 201, has a roughly mountain-shaped bend with a peak 205d in the center of the front-to-rear portion when viewed from the side (see Figure 18). When viewed from the side, the outer surface portion 205a has a shape in which the front side is narrower than the base side, which is the connecting side to the support plate 204.

[0156] The arm tip portion 202 is located on the front end side of the arm body portion 201. The arm tip portion 202 is located in front of the tip of the excavation claw 76 of the planting claw device 50. The arm tip portion 202 is a plate-shaped portion that is bent at a right angle to the left and right inward relative to the outer surface portion 205a of the cutter member 205, and is formed by the front surface portion 205b of the cutter member 205. In this way, the arm tip portion 202 connects the left and right outer ends, which are one end in the left-right direction, to the tip of the arm body portion 201, and is a portion that connects the left and right outer ends to the tip of the arm body portion 201.

[0157] The arm tip portion 202 is an inclined surface portion that slopes downward in the direction perpendicular to the claw extension direction when viewed from the side. The arm tip portion 202 is a plate-like portion that forms a straight line when viewed in a side cross-section (see Figure 22). Figure 22 is a left side cross-section of the groove-making arm 200 at the left-right center position. As shown in Figure 22, the arm tip portion 202 is a straight line when viewed in a side cross-section with the extension direction in a predetermined direction (see arrow Y1).

[0158] The arm tip portion 202 has a lower edge portion that protrudes downward from the tips of the arm body portion 201 and the auxiliary arm portion 203 as a tip projection portion 202a. The arm tip portion 202 has a downwardly convex mountain shape at its lower edge, with a vertex portion 202c formed by a pair of slanted edges 202b. The vertex portion 202c is an obtuse-angled corner formed by the pair of slanted edges 202b.

[0159] The auxiliary arm portion 203 is positioned offset from the planting claw 72 in the left-right direction, that is, towards the planting transmission case 51 (inward). In other words, the auxiliary arm portion 203 is located on the opposite side of the arm body portion 201 from the planting claw 72 in the left-right direction. The auxiliary arm portion 203 is a plate-shaped portion that is bent at a right angle toward the rearward side of the front surface portion 205b of the cutter member 205, with the left-right direction being the thickness direction, and is formed by the inner surface portion 205c of the cutter member 205. Thus, the auxiliary arm portion 203 has one end, the front end, connected to the left and right inner sides of the other end in the left-right direction of the arm tip portion 202, and the front end is connected to the left and right inner sides of the arm tip portion.

[0160] The auxiliary arm portion 203 is a relatively narrow portion of the cutter member 205 with respect to the outer surface portion 205a, has a substantially constant width, and in a side view, is inclined in substantially the same direction as the front part of the outer surface portion 205a and extends in a substantially straight line. The auxiliary arm portion 203 has a sharp tip portion 203a that forms an acute angle on the upper side of its rear end. In the state shown in Figure 19, the auxiliary arm portion 203 is positioned near the rear on the left and right inner side (upper side in Figure 19) of the claw body portion 82 of the planting claw 72.

[0161] The cutter member 205 is fixed to the support plate 204 by two bolts 206 which serve as fixing members. The two bolts 206 are located on both sides in the width direction of the arm 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 a hole 205e formed at the rear end of the outer surface portion 205a and are screwed into threaded holes formed at the front end of the support plate 204.

[0162] The hole 205e through which the bolt 206 passes is an elongated hole whose longitudinal direction is aligned with the direction in which the cutter member 205 extends from the support plate 204. This allows for adjustment of the fixing position of the cutter member 205 relative to the support plate 204 in the direction of extension. Adjusting the fixing position of the cutter member 205 relative to the support plate 204 involves adjusting the position of the arm tip 202 in the direction of moving it closer to or further away from the tip of the planting claw 72.

[0163] The link mechanism 300 will now be described. The link mechanism 300 supports the furrowing arm 200 so that it can reciprocate in the front-rear direction with respect to the retaining plate support portion 75 that constitutes the planting claw device 50. The retaining plate support portion 75 is fixed at multiple points by bolts 88 to the case body 70a that constitutes the base portion 70 of the planting claw device 50. The retaining plate support portion 75 has an outer shape that is roughly rectangular or roughly trapezoidal in side view, and its lower edge is a downward projection portion 75a that protrudes below the case body 70a that constitutes the base portion 70 (see Figure 18). The retaining plate support portion 75 is located below the arm portion 71.

[0164] The link mechanism 300 includes two link arms: a front arm 301, which is a first link arm located at the front, and a rear arm 302, which is a second link arm located at the rear. The front arm 301 and the rear arm 302 are linear plate-shaped members with the left-right direction as the plate thickness direction.

[0165] The front arm 301 and the rear arm 302 are rotatably supported at one end in the longitudinal direction by the retaining plate support portion 75 on the planting claw device 50 side, and at the other end by the rotatably supported on the furrowing arm 200 side. Both arms 301 and 302 have approximately the same length and are installed so as to be approximately parallel to each other. Both arms 301 and 302 are installed at positions to the left and right outer of the retaining plate support portion 75, and at positions to the left and right inner of the support plate 204 that constitutes the furrowing arm 200. In other words, both arms 301 and 302 are located between the retaining plate support portion 75 and the support plate 204 in the left-right direction.

[0166] The front arm 301 and the rear arm 302 are each rotatably supported at their lower ends by a shaft-shaped pivot member 305 or the like, via a bearing member (not shown), on the front boss portion 303 and the rear boss portion 304, which are provided on the front and rear of the downward projection 75a of the retaining plate support portion 75. The front boss portion 303 and the rear boss portion 304 are cylindrical projections on both the left and right sides of the plate-shaped main body portion of the retaining plate support portion 75. The pivot point at the lower end of the front arm 301 relative to the front boss portion 303 is designated as the front fixed pivot point 311, and the pivot point at the lower end of the rear arm 302 relative to the rear boss portion 304 is designated as the rear fixed pivot point 312 (see Figure 18).

[0167] The front arm 301 is rotatably supported at its upper end by a support bolt 307 or the like, via a bearing member (not shown), on a boss portion 306 located approximately in the center of the support plate 204. The boss portion 306 is a cylindrical projection on both the left and right sides of the plate-shaped main body portion of the support plate 204, and is located behind the portion of the support plate 204 that receives the fixing of the outer surface portion 205a of the cutter member 205. The pivot support portion of the upper end of the front arm 301 relative to the boss portion 306 is designated as the front movable pivot support portion 313 (see Figure 18).

[0168] The rear arm 302 has its upper end 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.

[0169] The connecting plate 310 is a plate-like member with a roughly rounded rectangular or roughly elliptical shape, located on the left and right inner sides of the rear end of the support plate 204, and is oriented so that its longitudinal direction is the width direction of the support plate 204. The connecting plate 310 is positioned so that, in a side view, its entirety is within the outer shape of the support plate 204. The connecting plate 310 has a boss portion 321 approximately in the center.

[0170] The rear arm 302 is rotatably supported at its upper end by a bearing member (not shown) via a pivot bolt 322 or the like, which is a pivot support member, against the boss portion 321 of the connecting plate 310. The boss portion 321 is a cylindrical projection on both the left and right sides of the plate-shaped main body portion of the connecting plate 310. The support plate 204 has a relief hole 204a formed through it to avoid interference with the boss portion 321 of the connecting plate 310. The pivot support portion of the upper end of the rear arm 302 relative to the boss portion 321 is designated as the rear movable pivot support portion 314 (see Figure 18).

[0171] The connecting plate 310 is fixed to the support plate 204 at two points by bolts 323, which serve as fixing members, at both ends in its longitudinal direction. The bolts 323 pass through holes 204b formed in the rear of the support plate 204 and are screwed into threaded holes formed in the connecting plate 310. The fixing points by the bolts 323 are located on both sides of the boss portion 321 in the longitudinal direction of the connecting plate 310.

[0172] The hole 204b through which the bolt 323 passes is an elongated hole whose longitudinal direction is aligned with the longitudinal direction of the groove-making arm 200 in a side view. This allows for adjustment of the fixing position of the connecting plate 310 relative to the support plate 204. Adjusting the fixing position of the connecting plate 310 relative to the support plate 204 is equivalent to adjusting the position of the rear-moving shaft support 314 on the support plate 204.

[0173] In other words, by adjusting the fixing position of the connecting plate 310 relative to the support plate 204, the interaxial distance L1 (see Figure 20) between the pivot axis Q3 of the front movable shaft support 313 and the pivot axis Q4 of the rear movable shaft support 314 is adjusted. The relief hole 204a for the boss portion 321 has a length such that the boss portion 321 does not interfere with the support plate 204 within the range of position adjustment of the connecting plate 310 by the hole 204b in the support plate 204, and is formed as an elongated hole aligned longitudinally with the hole 204b.

[0174] As described above, the link mechanism 300, which includes the two arms, the front arm 301 and the rear arm 302, is a four-bar link configuration in which the axes of the four pivot points—the front fixed pivot point 311, the rear fixed pivot point 312, the front movable pivot point 313, and the rear movable pivot point 314—are the nodes, and it movably connects and supports the furrowing arm 200 with respect to the holding plate support part 75. The link mechanism 300 moves the front movable pivot point 313 and the rear movable pivot point 314, which are provided on the furrowing arm 200 side, by rotating both arms 301 and 302 relative to the front fixed pivot point 311 and the rear fixed pivot point 312, whose positions are fixed relative to the planting claw device 50 side.

[0175] The front arm 301 and the rear arm 302 rotate around the pivot points of the front fixed pivot 311 and the rear fixed pivot 312, respectively, thereby moving the furrowing arm 200 back and forth relative to the planting claw device 50. During the reciprocating movement of the furrowing arm 200, the distance between the axes of the front fixed pivot 311 and the rear fixed pivot 312 (the distance between the pivot axis Q1 of the front fixed pivot 311 and the pivot axis Q2 of the rear fixed pivot 312), and the distance between the axes of the front moving pivot 313 and the rear moving pivot 314 (the distance between the pivot axis Q3 and the pivot axis Q4) remain constant.

[0176] As described above, the furrowing arm 200, which is movably supported by the link mechanism 300, has two positional orientations during its reciprocating motion, namely, its positional orientation relative to the planting claws 72: a standby orientation (see Figure 20) and a furrowing orientation (see Figure 18). The standby orientation of the furrowing arm 200 is the positional orientation at the time when the planting claws 72 cut the seedling mat 100. The furrowing orientation of the furrowing arm 200 is the positional orientation when it has moved forward relative to the planting claws 72 when planting seedlings (seedling blocks 110) in the field. Figure 19 shows the state in which the furrowing arm 200 is in the furrowing orientation.

[0177] The link mechanism 300 biases the groove-making arm 200 toward the groove-making position by the groove-making arm return spring 330. The groove-making arm return spring 330 is a so-called torsion spring and has extensions 330a and 330b at both ends of the coil-shaped portion (see Figure 18). The groove-making arm return spring 330 is provided at the front fixed shaft support 311 with the coil-shaped portion fitted onto the front boss portion 303.

[0178] The groove-making arm return spring 330 has one extension portion 330a that extends to the rear and contacts the rear boss portion 304 from above, while the other extension portion 330b is locked to the front arm 301. The other extension portion 330b is locked to the front arm 301 by bending its tip and contacting the rear side of the middle portion of the front arm 301.

[0179] The groove-making arm return spring 330 biases the front arm 301 relative to the retaining plate support 75 in the direction that the groove-making arm 200 moves forward, i.e., in a left rotation direction when viewed from the left side, by biasing the extensions 330a and 330b apart (see Figure 18, arrow J1). As a result, the groove-making arm 200 is biased toward the groove-making position relative to the planting claw device 50.

[0180] The furrowing arm 200 moves back and forth relative to the planting claw device 50 in conjunction with the rotational movement of the planting claw device 50 relative to the rotary case 52, which performs a predetermined planting operation in conjunction with the rotation of the rotary case 52. The furrowing arm 200 performs a periodic reciprocating motion with respect to the rotational movement of the planting claw device 50 relative to the rotary case 52, with one rotation equaling one cycle. 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 axis 50a (see Figure 3).

[0181] The furrowing arm 200 reciprocates in conjunction with the relative rotational movement of the planting claw device 50 relative to the rotary case 52 around 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 rotational movement of the front arm 301 and rear arm 302 of the link mechanism 300, thereby causing the furrowing arm 200 to reciprocate.

[0182] The groove-making arm 200 changes its relative position and orientation to the planting claws 72 in conjunction with the movement of the planting claws 72, via a cam mechanism 400 that includes a cam plate 410 acting as a cam. The cam plate 410 is provided on a rotary case 52 that rotatably supports the planting claw device 50 including the planting claws 72, and changes the relative position of the groove-making arm 200 to the planting claws 72 as the planting claw device 50 rotates.

[0183] The cam plate 410 is a roughly disc-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 oriented with its thickness in the left-right direction and is interposed between the rotary case 52 and the case body 70a of the planting claw device 50 (see Figure 19).

[0184] As shown in Figure 23, the cam plate 410 has an outer shape (plate surface shape) in which a portion of the circular outer circumference is cut off in a substantially straight line. The outer surface of the cam plate 410, which forms the outer shape of the cam plate 410 when viewed in the axial direction of the central axis P1 along the left-right direction, is the cam surface 411 which acts as the surface acting on the guide roller 402 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). Figure 23 shows an example of the shape of the cam surface 411.

[0185] As shown in Figure 23, the 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 the first arc-shaped cam surface portion 412 with respect to the position of the central axis P1. Both the first arc-shaped cam surface portion 412 and the second arc-shaped cam surface portion 413 have an arc shape centered on the position of the central axis P1 of the cam plate 410. The cam plate 410 has a shape that is symmetrical with respect to a predetermined straight line P2 passing through the central axis P1.

[0186] In this embodiment, the radius of the circumferential shape along which the second arc cam surface 413 follows is approximately 1 / 3 of the radius of the circumferential shape along which the first arc cam surface 412 follows. The first arc cam surface 412 is formed over an angular range of approximately 260° in the circumferential direction around the central axis P1. The second arc cam surface 413 is formed over an angular range of approximately 45° in the circumferential direction around the central axis P1.

[0187] On the cam surface 411, a linear cam surface 414 is formed between the ends of the first arc-shaped cam surface portion 412 and the second arc-shaped cam surface portion 413. The linear cam surface 414 is located on both sides of the straight line P2. The linear cam surface 414 smoothly connects the ends of the first arc-shaped cam surface portion 412 and the second arc-shaped cam surface portion 413.

[0188] Furthermore, the cam mechanism 400, as a configuration provided on the planting claw device 50 side, includes a guide roller 402 that acts on the cam plate 410 and a roller support arm 403 that supports the guide roller 402 with respect to the retaining plate support portion 75.

[0189] The roller support arms 403 are provided on the left and right inner sides relative to the retaining plate support portion 75. The roller support arms 403 are arm-shaped members, and one end of each end is rotatably supported by a bolt-shaped pivot member 404 or the like, via a bearing member (not shown), relative to the front boss portion 303 that supports the front arm 301 (see Figure 19).

[0190] The roller support arm 403 is positioned so as to align its pivot axis with that of the front arm 301 and to maintain its positional relationship with the front arm 301 in the direction of rotation. In other words, the roller support arm 403 and the front arm 301 are coaxially supported at the front fixed shaft support portion 311 by the front boss portion 303, and are fixed to each other so as to rotate integrally around the axis of the pivot axis Q1.

[0191] The guide roller 402 is a cylindrical rotating body located to the right of the tip of the roller support arm 403, and is rotatably supported by a predetermined pivot member on the roller support arm 403 with the left-right direction as the axis of rotation. The guide roller 402 is supported by the roller support arm 403 in a position where it contacts the cam plate 410 from below.

[0192] As shown in Figure 18, the front arm 301 extends upward from the front boss portion 303, while the roller support arm 403 extends backward. The front arm 301 and the roller support arm 403 are positioned at an angle of approximately 80 to 90° in the axial view of the pivot axis Q1. The angle between the front arm 301 and the roller support arm 403 is the angle β1 formed by the straight line connecting the pivot axis Q1 of the front fixed pivot support portion 311 and the pivot axis Q3 of the front movable pivot support portion 313, and the straight line connecting the pivot axis Q1 and the pivot axis Q5, which is the rotation center of the guide roller 402 (see Figure 20).

[0193] The guide roller 402 is biased in a direction that presses it against the cam plate 410 via the roller support arm 403 by the biasing force on the front arm 301 by the groove-making arm return spring 330. As a result, the guide roller 402 moves along the cam surface 411 in conjunction with the relative rotation of the planting claw device 50.

[0194] With the above configuration, the contact position of the guide roller 402 with respect to the cam plate 410 changes in the direction of approaching or moving away from the central axis P1 of the cam plate 410, in accordance with the change in the distance of the cam surface 411 from the central axis P1 of the cam plate 410 due to the relative rotation of the planting claw device 50. This movement of the guide roller 402 results in the integrated rotation of the roller support arm 403 and the front arm 301 around the pivot axis Q1. The rotation of the front arm 301 activates the link mechanism 300, causing the furrowing arm 200 to perform a predetermined operation. In this way, in the link mechanism 300, the front arm 301 becomes a drive arm that reciprocates by receiving power transmission from the cam mechanism 400 in accordance with the relative rotation of the planting claw device 50, and operates the link mechanism 300 to reciprocate the furrowing arm 200.

[0195] Figures 24 to 28 will be used to explain the operation of the cam mechanism 400, link mechanism 300, and furrowing arm 200 in conjunction with the relative rotation of the planting claw device 50. In Figures 24 to 28, for convenience, 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 around the claw-side rotation axis O2 (central axis P1 of the cam plate 410). As shown in Figures 24 to 28, in the relative rotation of the planting claw device 50, the rotary case 52 rotates counterclockwise relative to the planting claw device 50 in a left side view (see arrow M1).

[0196] The state in which the guide roller 402 is in contact with the first arc cam surface portion 412 of the cam plate 410 corresponds to the standby position of the groove-making arm 200, and the state in which the guide roller 402 is in contact with the second arc cam surface portion 413 of the cam plate 410 corresponds to the groove-making position of the groove-making arm 200. In other words, during the relative rotation of the planting claw device 50, when the guide roller 402 is in contact with the first arc cam surface portion 412, the groove-making arm 200 is in the standby position, and when the guide roller 402 is in contact with the second arc cam surface portion 413, the groove-making arm 200 is in the groove-making position.

[0197] Figure 24 shows the furrowing arm 200 in a standby position. In the state shown in Figure 24, the guide roller 402 is in contact with the starting end of the first arc cam surface portion 412 in the rotational direction of the cam plate 410 relative to the planting claw device 50.

[0198] Figure 25 shows the 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, the rotational position of the link mechanism 300 is maintained, and the standby position of the furrowing arm 200 is maintained while the guide roller 402 is in contact with the first arc cam surface portion 412.

[0199] As the relative rotation of the planting claw device 50 progresses, the contact position of the guide roller 402 with respect to the cam plate 410 moves from the first arc-shaped cam surface 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 position. That is, as the guide roller 402 moves relative to the linear cam surface 414 from the first arc-shaped cam surface 412, the guide roller 402 approaches the central axis P1 (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 Figure 26, arrow M2). 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 toward the front side, that is, toward the furrowing position.

[0200] Then, as shown in Figure 27, when the guide roller 402 reaches the second arc-shaped cam surface portion 413 from the end of the linear cam surface 414, the groove-making arm 200 assumes the groove-making position. As shown in Figures 27 and 28, when the guide roller 402 is positioned on the second arc-shaped cam surface portion 413, the groove-making arm 200 maintains the groove-making position.

[0201] As the relative rotation of the planting claw device 50 progresses, the contact position of the guide roller 402 with respect 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), causing the furrowing arm 200 to begin moving toward the standby position. That is, as the guide roller 402 moves relative to the first arc cam surface portion 412 from the linear cam surface 414, the guide roller 402 moves away from the central axis P1 (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 Figure 28, arrow M3). As a result, the link mechanism 300 rotates in a direction that tilts the front arm 301 toward the rear, and the furrowing arm 200 gradually moves toward the rear, that is, toward the standby position.

[0202] Then, as the guide roller 402 reaches the first arc-shaped cam surface portion 412 from the end of the linear cam surface 414, the furrowing arm 200 returns to its standby position (see Figure 24). The above operations are repeated in accordance with the relative rotation of the planting claw device 50.

[0203] As described above, the furrowing arm 200 is provided by a link mechanism 300 and a cam mechanism 400 to change its position and orientation relative to the planting claw 72 in conjunction with the relative rotation of the planting claw device 50, which is responsible for the operation of the planting claw 72. With this configuration, the shape of the cam surface 411 of the cam plate 410 adjusts the operating mode of the furrowing arm 200, which is linked to the relative rotation of the planting claw device 50. Specifically, by adjusting the shape of the cam surface 411, it becomes possible to adjust, for example, the timing at which the furrowing arm 200 starts moving from the standby position to the furrowing position, and the timing at which the furrowing arm 200 returns to the standby position.

[0204] The operation of the planting unit, which has the above configuration, will be explained with reference to Figures 29 to 35. The operation of the planting unit includes the planting of seedling blocks 110 by the planting claw device 50, and the furrowing and cutting of mulch film 250 by the furrowing arm 200, which is linked to the planting operation.

[0205] Figures 30 to 35 are left side views of the planting unit, with the direction of movement of the machine being to the left in each figure (see arrow N1). In addition, in each of Figures 30 to 35, in order to show the displacement of the planting unit relative to the field in the direction of machine movement, for convenience, only the seedling block 110 in the state planted in the field is shown.

[0206] In Figures 30 to 35, the trajectory E1 shown by the dashed line represents the trajectory traced by the tip of the planting claw 72, that is, the tip of the claw body 82. Trajectory E1 is a vertically elongated, roughly elliptical, closed (loop-shaped) trajectory. More specifically, trajectory E1 has a roughly elliptical shape with a convex bulge at the front and a flattened shape at the rear.

[0207] Furthermore, the trajectory E1 of the planting claws 72 is the trajectory of the seedling transplanter 1 as it moves forward relative to the field. In other words, trajectory E1 does not take into account the movement of the planting claws 72 relative to the field as the machine moves forward, and is a stationary trajectory based on the machine itself.

[0208] As shown in Figures 30 to 35, in the planting unit that moves forward as the machine moves forward, the drive shaft 52a of the rotary case 52 maintains a substantially constant height position relative to the field surface 91. In other words, during the operation of the planting unit as the machine moves forward, the case-side rotation shaft O1 traces a trajectory E2 parallel to the field surface 91 (see Figure 30).

[0209] 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 represents the phase [deg] of the planting claw device 50 in relative rotation around the claw-side rotation axis O2, that is, the relative angular position between the planting claw device 50 and the rotary case 52.

[0210] In Figure 29, graph Gr1, shown by a solid line, shows an example of the change in position of the furrowing arm 200 due to a change in the phase of the planting claw device 50, that is, the amount of rotation (arm rotation) [deg] of the roller support arm 403 by the cam plate 410. Graph Gr2, shown by a dashed line, shows an example of the change in the height of the planting claws 72 due to a change in the phase of the planting claw device 50. Here, the height of the planting claws 72 (planting claw height) is the height of the tip of the planting claws 72 relative to a predetermined reference height corresponding to the field surface 91, and is expressed as a ± value with a predetermined height position as the reference (0 [mm]).

[0211] First, as shown in Figure 30, the rotation of the rotary case 52 around the case-side rotation axis O1 and the relative rotation of the planting claw device 50 cause the planting claws 72 to scrape the unit block section 108. The state of the planting unit shown in Figure 30 corresponds to the state in the "scraping" phase range of the planting claw device 50 in the graph shown in Figure 29.

[0212] During the "scraping" phase, the furrowing arm 200 is in a standby position. That is, the guide roller 402 is in contact with the cam plate 410 at the first arc cam surface portion 412. In the operation of the cam mechanism 400, the position of the roller support arm 403 when the furrowing arm 200 is in the standby position is set as the reference position, i.e., the rotation amount is 0 [deg]. In this way, the seedling mat 100 is scraped by the planting claws 72 at a predetermined timing when the furrowing arm 200 is in the standby position.

[0213] Furthermore, regarding the height of the planting claws within the "scraping" range, the planting claws 72 are located at or near the height position h1 of the upper limit within their lifting range. Note that graph Gr2, which shows the change in planting claw height, forms a sinusoidal curve.

[0214] After the planting claws 72 scrape the unit block section 108, the planting claw device 50 rotates to move the planting claws 72 forward and downward towards the guide rail 48, as shown in Figure 31. The state of the planting unit shown in Figure 31 is within the "downward" phase range of the planting claw device 50 in the graph shown in Figure 29.

[0215] 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 a predetermined first phase t1, the furrowing arm 200, which is in the standby position, begins to move toward the furrowing position. That is, the guide roller 402 moves from the first arc cam surface 412 to one of the linear cam surfaces 414, and the amount of arm rotation begins to increase, as shown in graph Gr1.

[0216] During the "descending" phase, the arm rotation gradually increases, and the arm rotation reaches its maximum value U1 when the phase of the planting claw device 50 reaches a predetermined second phase t2. In other words, the furrowing arm 200 assumes the furrowing position.

[0217] 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 penetration (furrowing) of the furrowing arm 200 begins. The timing of the penetration of the furrowing arm 200 corresponds to the timing when the phase of the planting claw device 50 reaches a 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 creates furrows at the seedling planting locations in the field.

[0218] As shown in Figure 32, when the furrowing arm 200 penetrates the field, its tip portion, the lower edge of the arm tip 202, contacts the field surface 91. As described above, the arm tip 202 is a plate-like portion that forms a straight line in a side cross-sectional view (see Figure 22). The furrowing arm 200 is then inserted into the field surface 91 with its arm tip 202 in an upright position.

[0219] Thus, the furrowing arm 200 is positioned so that its tip 202 is upright relative to the field surface 91 when it enters the field surface 91. Here, the upright position of the arm tip 202 relative to the field surface 91 is defined as a state in which, as shown in Figure 32, the angle α1 between the extension direction V1 of the linearly oriented arm tip 202 and the field surface 91 is 45° or more in a side cross-sectional view. In the example shown in Figure 32, the angle α1 is approximately 60°.

[0220] Furthermore, the furrowing arm 200 is configured such that, in a side view, the extension direction of its tip portion is inclined downward relative to the field surface 91 when it enters the field surface 91. As shown in Figure 32, the extension direction V2 of the tip portion of the furrowing arm 200 in a side view is the extension direction of the tip portion of the edge of the outer surface portion 205a (see Figure 18), which has a roughly V-shaped bend in a side view. Note that the extension direction V2 coincides with or approximately coincides with the extension direction of the inner surface portion 205c (see Figure 21) of the furrowing arm 200 in a side view.

[0221] Regarding the inclination of the tip portion of the furrowing arm 200 in the extension direction V2, it is preferable that the angle α2 formed by the extension direction V2 of the tip portion of the furrowing arm 200 and the field surface 91 be 50° or less, as shown in Figure 32. In the example shown in Figure 32, the angle α2 is approximately 50°.

[0222] In the "soil penetration" range, as shown in graph Gr2, the planting claw height gradually decreases from the "downward" range, and when the planting claw 72 reaches the height position h2 or a nearby position at the lower end of its upward and downward range, the planting claw device 50 plants the seedling block 110. The state of the planting unit shown in Figure 33 is the state in the "planting" phase range of the planting claw device 50 in the graph shown in Figure 29.

[0223] Specifically, as shown in Figure 33, the seedling block 110 is held by the planting claw device 50, and at a predetermined timing when the tip of the planting claw 72 is located in the field below the field surface 91, the seedling block 110 is pushed out by the extrusion member 73 (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).

[0224] Meanwhile, in the furrowing position, the furrowing arm 200 begins to move toward the standby position when the phase of the planting claw device 50 reaches a predetermined fourth phase t4 during the "soil penetration" phase. That is, the guide roller 402 moves from the second arc cam surface 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 "planting" and the subsequent "storage" phase, and the furrowing arm 200 returns to the standby position when the phase of the planting claw device 50 reaches a predetermined seventh phase t7. The timing of the seventh phase t7 marks the end of the "storage" phase of the planting claw device 50.

[0225] Then, as the planting claws 72 return to the height position h1 of the raised end and the furrowing arm 200 returns to the standby state, the unit block section 108 is scraped by the planting claws 72 as described above. The operation of the planting unit as described above is performed continuously as a cycle as the machine moves forward.

[0226] In the example shown in graph Gr1 of Figure 29, the furrowing arm 200 gradually moves toward the storage position from the timing of the fourth phase t4, and temporarily stops within the "planting" range when the phase of the planting claw device 50 reaches a predetermined fifth phase t5. Thereafter, from the timing of a predetermined sixth phase t6 after the completion of planting, it starts moving toward the storage position.

[0227] Thus, the groove-making arm 200 is designed to return from the groove-making position to the standby position, via a groove-making completion position which is a stopped state between the fifth phase t5 and the sixth phase t6. In other words, the groove-making arm 200 is designed 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.

[0228] When the groove-making arm 200 is made to perform such a two-stage retraction operation, a third arc-shaped cam surface (not shown) is provided on the cam plate 410 at the location where the other (left side in Figure 23) linear cam surface 414 is formed, with respect to the phase of the cam surface 411. The third arc-shaped cam surface is a surface having an arc shape centered on the position of the central axis P1 of the cam plate 410. The radius of the circumferential shape along which the third arc-shaped cam surface follows is smaller than the radius of the circumferential shape along which the first arc-shaped cam surface 412 follows, and larger than the radius of the circumferential shape along which the second arc-shaped cam surface 413 follows.

[0229] In the operation of the planting unit as described above, the furrowing arm 200 is designed to perform a cyclical movement from the furrowing position to the standby position after the planting of seedlings in the field by the planting claws 72 is completed. That is, planting of seedlings by the planting claw device 50 takes place from the moment the furrowing arm 200 begins to move from the standby position to the furrowing position until the moment the furrowing arm 200 returns to the standby position.

[0230] Furthermore, in the operation of the planting unit, the furrowing arm 200 is positioned so that, when in the furrowing position, its tip protrudes forward of the planting claws 72, and it enters the field surface 91 before the planting claws 72. When planting seedlings with the planting claw device 50, as shown in Figure 32, the planting unit first applies the furrowing arm 200 to the field to create furrows, then applies the planting claws 72 to the field, and as shown in Figure 33, when the furrowing by the furrowing arm 200 is completed, it plants the seedlings, that is, pushes out the seedling blocks 110.

[0231] Furthermore, regarding the furrowing operation of the furrowing arm 200, the furrowing arm 200 is designed so as not to interfere with the seedling block 110, which is a seedling planted in the field, in the operating range in which at least the tip of the arm is positioned below the field surface 91. Specifically, as shown in Figures 32, 33, and 34, the furrowing arm 200 is designed so that the tip of the arm 202 passes under the seedling block 110, which is either a seedling block 110 planted at a predetermined planting position in the field by the planting claw device 50 (a hypothetically placed seedling block 110) or a seedling block 110 planted in the field.

[0232] Figures 32, 33, and 34 show the trajectory E3 of the arm tip 202 of the furrowing arm 200 as a dashed line. Trajectory E3 shows the trajectory of the lower edge of the arm tip 202. As shown by trajectory E3, the furrowing arm 200 penetrates the field surface 91 with its arm tip 202 from a position in front of the virtually placed seedling block 110 (Figures 32 and 33). Subsequently, the arm tip 202 moves to the underside of the virtually placed seedling block 110, and when it reaches the rear side of the virtually placed seedling block 110, the seedling block 110 is actually planted (see arrow R1 in Figure 33).

[0233] According to trajectory E3, the furrowing arm 200, with its tip 202 positioned below and behind the planted seedling block 110, moves its tip 202 upward and detaches from the field surface 91 (Figure 34). Subsequently, the furrowing arm 200 moves its tip 202 upward while slowly moving it towards the front of the seedling block 110 above it. Above the seedling block 110, trajectory E3 moves from the outside to the inside relative to the trajectory E1 of the planting claw 72 and intersects with trajectory E1 (Figure 34, see intersection R2).

[0234] In this manner, the furrowing arm 200 moves in a manner that, in a side view, the tip 202 of the arm passes from the front of the seedling block equivalent portion, under the seedling block equivalent portion with a gap, and then wraps around to the rear of the portion, relative to the portion where the seedling block 110 to be planted in the field is located and the seedling block 110 that has actually been planted (hereinafter referred to as the "seedling block equivalent portion"). In other words, at the point where the furrowing arm 200 turns from a downward movement to an upward movement, the tip 202 of the arm moves 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 Figure 29, the furrowing arm 200 reliably avoids contact with the seedling block 110 by performing the two-stage retraction movement described above.

[0235] Furthermore, regarding the operation of the furrowing arm 200, the furrowing arm 200 is positioned to trace a trajectory E3 at its tip that secures space for the planting claw 72, located at the lowest end, to push out the seedling block 110, which is a seedling held together with the holding plate 74 by the planting claw 72.

[0236] According to the furrowing arm 200, soil from the field is removed along the trajectory of the arm tip 202 to create a furrow. The furrowing arm 200 acts on the field such that the portion where soil is removed by its action, i.e., the furrowed 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 furrowing arm 200, the area enclosed by the roughly "U" shaped folded portion at the lower end is secured as the release space for the seedling blocks 110 when the furrowing by the furrowing arm 200 is completed.

[0237] The seedling transplanter 1, having the configuration described above, is equipped in the planting unit with a trajectory changing device 270 that changes the movement trajectory of the furrowing arm 200 relative to the planting claws 72 in order 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 distance between seedlings that are planted continuously at a predetermined interval in the front-rear direction relative to the field, i.e., the plant spacing.

[0238] As described above, the spacing between plants is changed by the rotational speed of the rotary case 52, which is changed by the speed change device 36 (see Figure 3) inside the plant spacing speed change case 33. In this embodiment, the speed change device 36 is configured to switch between two plant spacing dimensions: a relatively large plant spacing dimension (e.g., 40 cm) and a relatively small plant spacing dimension (e.g., 24 cm). If the trajectory of the furrowing arm 200 is constant regardless of the size of the plant spacing, the seedling planting performance may decrease, or the torque of furrowing on the soil may increase, leading to a greater load. Therefore, the trajectory changing device 270 changes the trajectory of the furrowing arm 200 according to the plant spacing.

[0239] The trajectory changing device 270 is composed of a link mechanism 300 that supports the furrowing arm 200 with respect to the planting claw device 50, which includes the planting claws 72. As described above, the link mechanism 300 is configured to operate in the form of a four-bar link with the axes (rotation axes) of the four pivot points as nodes, and is configured to change the trajectory of the furrowing arm 200, which moves back and forth between the standby position and the furrowing position, by changing the distance between the axes of the pivot points in the link mechanism 300.

[0240] The link mechanism 300, acting as a trajectory changing device 270, is configured to change the movement trajectory of the furrowing arm 200 relative to the planting claw 72 by changing the distance between the support parts of the two link arms, the front arm 301 and the rear arm 302, relative to the furrowing arm 200. In this embodiment, the axial distance L1 (see Figure 20) between the pivot axis Q3 of the front moving shaft support 313 and the pivot axis Q4 of the rear moving shaft support 314 corresponds to the distance between the support parts of the two link arms relative to the furrowing arm 200.

[0241] The distance L1 between axes is changed by adjusting the position of the rear movable shaft support 314 relative to the front movable shaft support 313. As described above, the position of the rear movable shaft support 314 is continuously adjustable within the range of the length of the holes 204b through which the bolts 323 pass at two locations, upper and lower, on the rear movable shaft support 314, based on the fixing position of the connecting plate 310 relative to the support plate 204. The position adjustment mechanism of the rear movable shaft support 314 functions as a mechanism for changing the trajectory of the groove-making arm 200 in the link mechanism 300 as a trajectory changing device 270.

[0242] 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 movable shaft support 314 is separated from the front movable shaft support 313 (the most separated state). In other words, the planting unit shown in Figures 18 and 20 has the longest inter-axis distance L1. Note that Figure 18 shows the furrowing arm 200 in the furrowing position, and Figure 20 shows the furrowing arm 200 in the standby position. The inter-axis distance L1 is maintained at a constant value regardless of the position of the furrowing arm 200.

[0243] On the other hand, in the planting units shown in Figures 36 and 37, the bolt 323 is positioned at the front end of the hole 204b, and the rear movable shaft support 314 is brought close to the front movable shaft support 313 (closest contact state). In other words, the planting units shown in Figures 36 and 37 have the shortest possible inter-axis distance L1. Note that Figure 36 shows the furrowing arm 200 in the furrowing position, and Figure 37 shows the furrowing arm 200 in the standby position. Hereafter, the state in which the inter-axis distance L1 is long, as shown in Figures 18 and 20, will be referred to as the "shaft support separated state," and the state in which the inter-axis distance L1 is short, as shown in Figures 36 and 37, will be referred to as the "shaft support close state."

[0244] The movement pattern of the furrowing arm 200, which reciprocates in the planting unit, changes as the interaxial distance L1 changes. Figure 38A shows the movement pattern of the furrowing arm 200 when the axial supports are separated, and Figure 38B shows the movement pattern of the furrowing arm 200 when the axial supports are close together. In Figures 38A and 38B, the furrowing arm 200 in the furrowing position is shown by a solid line, the furrowing arm 200A in the standby position is shown by a dashed line, and the furrowing arm 200B, which is between the standby position and the furrowing position, is shown by a double dashed line.

[0245] As shown in Figures 38A and 38B, the range of motion of the furrowing arm 200, which reciprocates in the planting unit, changes as the distance L1 between axes changes. Specifically, the range of motion of the furrowing arm 200 in a side view widens when the axis supports are closer together as shown in Figure 38B, compared to the state where the axis supports are separated as shown in Figure 38A. In the state where the axis supports are closer together, the range of motion of the furrowing arm 200 is mainly widened in the vertical direction as shown in the figure. In this way, either the state where the axis supports are separated or the state where the axis supports are closer together, which changes the operating mode of the furrowing arm 200, is used depending on the spacing between plants.

[0246] Figure 39 shows the movement trajectories of the planting claws 72 and furrowing arm 200 when the planting unit is in close proximity to the axis support and the spacing between plants is relatively large (for example, 40 cm). In Figure 39, the trajectory W1 shown by the dashed line is the trajectory traced by the tip of the planting claw 72, that is, the tip of the claw body 82. The trajectory W2 shown by the dashed line is the trajectory traced by the tip projection 202a of the arm tip 202 of the furrowing arm 200.

[0247] The trajectory W1 of the planting claws 72 and the trajectory W2 of the furrowing arm 200 are the trajectories of the planting claws 72 and the furrowing arm 200, respectively, as they perform predetermined operations while moving forward relative to the field along with the forward-moving body of the seedling transplanter 1. In other words, trajectories W1 and W2 take into account the movement of the planting claws 72 and the furrowing arm 200 relative to the field accompanying the forward movement of the machine, and are trajectories based on the field side.

[0248] As described above, the planting claws 72, which trace a loop-shaped trajectory (see trajectory E1 in Figure 30) relative to the machine body, repeatedly trace a trajectory that forms a downward curve due to the downward movement while moving forward, and a trajectory that forms an upward curve due to the upward movement while moving forward, as shown in trajectory W1 in Figure 39. Trajectory W1 has a vertically elongated loop-shaped trajectory portion W1a at the point where it turns from the downward movement to the upward movement.

[0249] For the planting claws 72, which operate periodically to trace a loop-shaped trajectory relative to the machine body, the distance of one cycle in the trajectory W1, taking into account the forward movement relative to the field, corresponds to the plant spacing dimension S1. In other words, as the machine body moves forward, the planting claws 72 perform a predetermined planting operation, repeating the movement that traces the trajectory W1 shown in Figure 39.

[0250] The trajectory W2 of the furrowing arm 200 is a trajectory that includes a periodic reciprocating motion, which is the relative motion of the furrowing arm 200 to the planting claw 72, in addition to the movement of the planting claw 72. The trajectory W2 of the furrowing arm 200 is generally similar to the trajectory W1 of the planting claw 72, having a downward-sloping trajectory portion, an upward-sloping trajectory portion, and a loop-shaped trajectory portion W2a that is a return portion. The loop-shaped trajectory portion W2a in trajectory W2 includes a portion corresponding to the trajectory E3 of the furrowing arm 200, in which the arm tip 202 moves in a manner that makes 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).

[0251] Therefore, in the trajectory W2 of the furrowing arm 200, the portion corresponding to the seedling block will be located within the loop-shaped trajectory portion W2a. It is preferable that the loop-shaped trajectory portion W2a of the trajectory W2 of the furrowing arm 200 passes close to the portion corresponding to the seedling block without interfering with it. In other words, it is preferable that the trajectory portion W2a of the furrowing arm 200 at the return portion of the trajectory W2 be drawn with the minimum necessary loop shape so as not to interfere with the portion corresponding to the seedling block (see the portion enclosed by the dashed circle X1 in Figure 39).

[0252] Figure 40 shows the movement trajectory of the planting claws 72 and furrowing arm 200 when the planting unit is in close proximity to the axis support and the spacing between plants is relatively small (for example, 24 cm).

[0253] When the spacing between plants is relatively small, the amount of movement of the planting claws 72 during the planting operation is greater relative to the amount of forward movement of the machine (the operation becomes faster). As a result, as shown in Figure 40, compared to the case where the spacing between plants is relatively large (Figure 39), the distance of one cycle corresponding to the spacing dimension S2 becomes shorter, and the loop-shaped trajectory portion W1a of the planting claws 72 becomes larger.

[0254] Therefore, as shown in Figure 40, when the spacing between plants is relatively small, the loop-shaped trajectory portion W2a of the furrowing arm 200, which positions the seedling block equivalent portion inside, becomes larger. In other words, the trajectory W2 of the furrowing arm 200 traces a trajectory that bypasses the seedling block equivalent portion (see the area enclosed by the dashed circle X2 in Figure 40).

[0255] An increase in the trajectory portion of the furrowing arm 200's trajectory W2 around the seedling block corresponds to an increase in the excavated portion of the field by the furrowing arm 200, i.e., the transplanting hole for transplanting seedlings. When the transplanting hole becomes larger, problems may arise such as a decrease in seedling planting performance or an increase in the torque of furrowing by the furrowing arm 200, leading to a greater load.

[0256] Therefore, when the spacing between plants is relatively small, the position adjustment mechanism of the rear-moving shaft support 314 in the link mechanism 300 switches the state of the planting unit from a state where the shaft support is close and the operating range of the furrowing arm 200 is relatively wide (see Figure 38B) to a state where the shaft support is farther away and the operating range of the furrowing arm 200 is relatively narrow (see Figure 38A). As a result, the portion of the trajectory of the furrowing arm 200 around the seedling block in the trajectory W2 becomes smaller.

[0257] Figure 41 shows the movement trajectories of the planting claws 72 and furrowing arm 200 when the planting unit is in a state where the axis support is separated and the spacing between plants is relatively small (e.g., 24 cm). As shown in Figure 41, when the planting unit is in a state where the axis support is separated, the loop-shaped trajectory portion W2a of the furrowing arm 200 becomes smaller in the trajectory W2 when the spacing between plants is relatively small. In other words, similar to the trajectory W2 of the furrowing arm 200 shown in Figure 39, the trajectory portion W2a of the furrowing arm 200 at the turning point is drawn with the minimum necessary loop shape so as not to interfere with the seedling block equivalent portion, and the transplanting hole is prevented from becoming unnecessarily large (see the area enclosed by the dashed circle X3 in Figure 41).

[0258] In this way, the trajectory W2 of the furrowing arm 200 is optimized by using either a state where the planting unit's axis support is close or a state where the axis support is farther away, depending on the size of the plant spacing changed by the gear change device 36 (see Figure 3) in the plant spacing case 33. However, if the plant spacing is relatively large, say S1 (for example, 40 cm), and the planting unit is set to the state where the axis support is farther away, the loop-shaped portion of the furrowing arm 200's trajectory W2 becomes smaller, making interference with the seedling block more likely.

[0259] According to the seedling transplanter 1 of this embodiment, which has the above configuration, interference of the furrowing arm 200 with the planted seedlings can be suppressed, and good planting performance can be obtained.

[0260] The planting unit of the seedling transplanter 1 is configured to take a standby posture at the timing of cutting the seedling mat 100 and a furrowing posture moved forward with respect to the planting claws 72 as the position and orientation of the furrowing arm 200. According to such a configuration, by changing the posture of the furrowing arm 200, it is possible to start furrowing by the furrowing arm 200 before the planting timing of the seedlings by the planting claws 72 while avoiding interference with the guide rail 48. Thereby, the degree of freedom of the relative position of the furrowing arm 200 with respect to the planting claws 72 can be improved, so that it is possible to respond to changes in the seedling planting conditions. Therefore, the seedling planting accuracy can be improved, and problems such as an increase in the torque of furrowing on the soil and interference of the furrowing arm 200 with the planted seedlings can be solved, and good planting performance can be obtained.

[0261] Further, the furrowing arm 200 is provided so as to perform a cyclic operation of returning from the furrowing posture to the standby posture after the planting of the seedlings by the planting claws is completed. According to such a configuration, after the planting of the seedlings is completed, the relative position and orientation of the furrowing arm 200 with respect to the planting claws 72 can be changed, and it is possible to perform a furrowing operation suitable for the planting of the seedlings. In particular, by configuring the furrowing arm 200 to perform a two-stage retraction operation as described above, it is possible to perform a furrowing operation more suitable for the planting of the seedlings. Further, when the furrowing arm 200 returns to the standby posture after the furrowing is completed, it is possible to prevent the furrowing arm 200 from getting in the way, for example, the furrowing arm 200 interfering with the guide rail 48, when scraping the next unit block portion 108 by the planting claws 72.

[0262] In addition, the furrowing arm 200 is provided such that in the furrowing posture, the tip projects forward of the planting claw 72 and enters the field surface ahead of the planting claw 72. According to such a configuration, when planting the seedlings with the planting claw 72, furrowing is performed by the furrowing arm 200. Therefore, the seedlings can be surely planted in the portion furrowed by the furrowing arm 200, and the planting resistance can be reduced. By reducing the planting resistance of the seedlings, it is possible to easily ensure the strength required for the planting claw 72 and its support structure against the planting resistance. Thereby, the planting unit and thus the seedling planting device 43 can be made smaller and lighter. Further, in the case of a field where the mulch film 250 is laid on the field surface 91, since the mulch film 250 is cut open by the furrowing arm 200 and furrowing is performed before the planting claw 72 enters the field surface, smooth and stable seedling planting can be performed.

[0263] In addition, the furrowing arm 200 is provided so as to draw a locus (see FIG. 32, locus E3) that does not interfere with the seedling block 110 planted in the field and passes near the seedling block 110 in the operating range where the arm tip 202 is positioned below the field surface. According to such a configuration, by furrowing at the minimum depth at which the tip of the furrowing arm 200 does not interfere with the seedling block 110, the torque of furrowing and the driving torque of the planting claw device 50 can be reduced, and the planting unit and thus the seedling planting device 43 can be made smaller and lighter. Further, by reducing these torques, it is possible to easily ensure the driving force of the planting claw device 50 and the strength of the drive system. In addition, since it is possible to suppress the furrowing depth by the furrowing arm 200 from becoming deeper than necessary, the planting posture of the seedling block 110 in the field can be stabilized, and good planting performance can be obtained.

[0264] Furthermore, the furrowing arm 200 is designed to change its position and orientation in conjunction with the movement of the planting claws 72. With this configuration, the movement of the furrowing arm 200 is automatically changed in accordance with the change in the movement of the planting claws 72 due to the change in the plant spacing by the speed change device 36 in the plant spacing speed change case 33. Therefore, it is not necessary to adjust the timing of the movement of the furrowing arm 200 when the plant spacing is changed.

[0265] Furthermore, the furrowing arm 200 is provided with a cam mechanism 400 including a cam plate 410 so as to change its position and orientation in conjunction with the movement of the planting claws 72. With this configuration, the relative rotation of the planting claw device 50 can be used as the operation to link the furrowing arm 200 to the movement of the planting claws 72 with a simple configuration. This makes it possible to link the furrowing arm 200 to the movement of the planting claws 72 while making the configuration of the seedling planting device 43 more compact, without having to provide a separate drive source or the like.

[0266] Furthermore, the furrowing arm 200 is configured so that the plate-shaped arm tip 202 is upright relative to the field surface when it enters the field surface. With this configuration, the contact area between the furrowing arm 200 and the field surface when it enters the field can be reduced, thereby reducing the torque of furrowing by the furrowing arm 200 and the driving torque of the planting claw device 50, and enabling the seedling planting device 43 to be made smaller and lighter. In particular, by aligning the linear extension direction of the arm tip 202 in a side cross-sectional view (see arrow Y1 in Figure 22) with the trajectory of the tip projection 202a during furrowing, the torque of furrowing by the furrowing arm 200 and the driving torque of the planting claw device 50 can be effectively reduced. Furthermore, in fields where mulch film 250 is laid on the field surface 91, the arm tip 202 can smoothly cut the mulch film 250, enabling smooth and stable planting of seedlings.

[0267] Furthermore, the groove-making arm 200 has a convex mountain shape on the lower side of the arm tip 202. With this configuration, the contact point of the lower end of the arm tip 202 with the mulch film 250 becomes the starting point for cutting the mulch film 250, and a smooth cutting action on the mulch film 250 by the groove-making arm 200 can be obtained.

[0268] Furthermore, the furrowing arm 200 is positioned such that the movement trajectory of the arm tip 202 is such that it creates space for pushing out the seedling block 110 held by the planting claw 72 located at the lowest end. With this configuration, the furrowing depth created by the furrowing arm 200 can be set to the minimum depth necessary for pushing out the seedling block 110, thereby reducing the torque of furrowing by the furrowing arm 200 and making it easier to ensure the strength of the furrowing arm 200. In addition, since the seedling block 110 can be reliably planted in the furrow created by the furrowing arm 200, good planting performance can be obtained.

[0269] Furthermore, the furrowing arm 200 has an arm body portion 201 positioned offset to one side in the left-right direction relative to the planting claw 72, and an arm tip portion 202 positioned at the tip of the arm body portion 201. With this configuration, since the arm body portion 201 of the furrowing arm 200 is offset in the left-right direction relative to the planting claw 72, the furrowing arm 200 can be laid out so that the arm body portion 201 overlaps the planting claw 72 in a side view. This reduces the volume of the portion of the furrowing arm 200 that enters the soil, thereby reducing the torque of furrowing by the furrowing arm 200 and making it easier to ensure the strength of the furrowing arm 200. In addition, since the arm body portion 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.

[0270] Furthermore, the furrowing arm 200 has an auxiliary arm portion 203 positioned offset from the main arm portion 201 in the left-right direction relative to the planting claws 72, and is configured in a roughly "U" shape by the main arm portion 201, the arm tip portion 202, and the auxiliary arm portion 203. With this configuration, good furrowing action can be obtained by the furrowing arm 200. In addition, in the case of a field where mulch film 250 is laid on the field surface 91, the main arm portion 201 and the auxiliary arm portion 203 can cut the mulch film 250 from both the left and right sides of the planting claws 72. As a result, the mulch film 250 at the planting portion of the planting claws 72 can be reliably cut and removed (peeled off), so that any remaining mulch film 250 can be suppressed and good planting performance can be obtained.

[0271] Furthermore, the seedling transplanter 1 is equipped with a trajectory changing device 270, which is a means for changing the movement trajectory of the furrowing arm 200 relative to the planting claws 72 in order to accommodate changes in the spacing between plants. With this configuration, the trajectory of the furrowing arm 200 can be adjusted to the optimal trajectory according to soil conditions, seedling conditions, etc., thereby ensuring planting performance under various conditions.

[0272] Furthermore, the trajectory changing device 270 allows the trajectory of the furrowing arm 200 to be changed so that the arm tip 202 traces a substantially constant trajectory, for example, by switching between plant spacing dimensions S1 (e.g., 40 cm) and S2 (e.g., 24 cm) as described above. This prevents the transplanting holes from becoming unnecessarily large, thereby achieving good planting performance and accuracy, and also prevents the furrowing load on the furrowing arm 200 from becoming unnecessarily large. Thus, the trajectory changing device 270 allows the trajectory of the furrowing arm 200 to be set to an optimal trajectory according to the plant spacing, so problems such as the trajectory of the furrowing arm 200 becoming unnecessarily large when the plant spacing is relatively small as described above (see Figure 40, area enclosed by dashed circle X2) can be suppressed.

[0273] Furthermore, the trajectory changing device 270 is composed of a link mechanism 300 that supports the furrowing arm 200 with respect 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.

[0274] Furthermore, the link mechanism 300, which functions as the trajectory changing device 270, is configured to change the trajectory of the groove-making arm 200 by changing the interaxial distance L1 (see Figure 20), which is the distance between the support parts of each link arm, the front arm 301 and the rear arm 302, relative to the groove-making arm 200. With this configuration, the trajectory changing device 270 can be realized with a simple structure. In addition, the trajectory of the groove-making arm 200 can be changed by the simple operation of changing the support position of one of the link arms. Moreover, with the interaxial distance L1 adjustment mechanism, the state of change in the trajectory of the groove-making arm 200 can be easily confirmed by visually observing the support position of the link arm.

[0275] Furthermore, the link mechanism 300 is configured such that the distance L1 between axes is adjusted by the fixing position of the connecting plate 310, which is provided with the rear-moving shaft support 314, relative to the furrowing arm 200. With this configuration, the trajectory of the furrowing arm 200 can be easily changed without replacing any parts. In addition, the bolts 323 for fixing the connecting plate 310 to the furrowing arm 200 are provided so that they can be operated from the left and right outer sides relative to the planting claw device 50, thus providing good operability for the bolts 323 and allowing the trajectory of the furrowing arm 200 to be easily changed.

[0276] In this embodiment, the adjustment mechanism for the inter-axis distance L1 is configured such that the hole 204b through which the bolt 323 passes in the furrowing arm 200 is an elongated hole, allowing for stepless adjustment. However, the configuration is not limited to this. For example, the furrowing arm 200 may have multiple holes through which the bolt 323 passes in, spaced at predetermined intervals in the position adjustment direction of the rear-moving shaft support 314. Specifically, for example, when corresponding to plant spacing of 40 cm and 24 cm as described above, two holes for which the bolt 323 passes in will be formed in the support plate 204: one corresponding to the state where the shaft support is close and another corresponding to the state where the shaft support is far apart. With such a configuration, it becomes possible to adjust the inter-axis distance L1 in steps to a preset value, making it possible to set an appropriate inter-axis distance L1 corresponding to the switching state between short and long plant spacing.

[0277] Furthermore, the planting claw device 50 has excavating claws 76 on the lower side of the holding plate 74. With this configuration, since the excavating claws 76 excavate the field before the holding plate 74, even if the field is made of 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. In addition, if there is mulch film 250 in the field, the excavating claws 76 can prevent the mulch film from becoming entangled with the holding plate 74.

[0278] Furthermore, the furrowing arm 200 is configured such that, at the moment it enters the field surface, the extension direction of its tip portion is inclined downwards relative to the field surface 91. With this configuration, for example, compared to a configuration in which the furrowing arm 200 penetrates the field surface 91 with its tip portion standing vertically, the uplift of soil during furrowing by the furrowing arm 200 can be suppressed, and the movement of soil during furrowing can be inhibited. As a result, the reduction of soil around seedlings due to furrowing by the furrowing arm 200 can be suppressed, and the holes created by the furrows can be made relatively small, so that a sufficient amount of covering soil can be secured for the planted seedlings.

[0279] [Second Embodiment] A second embodiment of the planting unit according to the present invention will be described with reference to Figures 42 to 46. In each embodiment described below, the same names or reference numerals will be used for components that are common to or correspond to those in the first embodiment described above, and explanations of redundant content will be omitted as appropriate. The planting unit according to this embodiment differs from the planting unit according to the above embodiment in terms of the configuration of the furrowing arm.

[0280] The furrowing arm 500 according to this embodiment is configured in a longitudinal shape and is positioned so that its longitudinal direction is aligned with the direction of claw extension. The furrowing arm 500 is positioned near the planting claw 72 relative to the planting claw device 50. Furthermore, the furrowing arm 500 is supported by a link mechanism 300 so as to be movable relative to the planting claw device 50 and is positioned to move relative to the planting claw 72.

[0281] The furrowing arm 500 is configured to be roughly "T" shaped in plan view, and has 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 body portion 501 and an arm tip portion 502 as the roughly "T" shaped outer portion. These portions constituting the furrowing arm 500 are provided as plate-like portions having a predetermined shape.

[0282] The furrowing arm 500 has a support plate 204 that forms the support base of the furrowing arm 500 and a cutter member 505 as its constituent members. The furrowing arm 500 has the same support configuration for the support plate 204 and the support configuration for the planting claw device 50 by the support plate 204 as the furrowing arm 200 of the embodiment described above. The support plate 204 and the cutter member 505 are connected and fixed to each other, forming an integrated furrowing arm 500.

[0283] The cutter member 505 is a bent plate-shaped member that forms approximately a "T" shape in plan view, and constitutes the main body portion of the groove-making arm 500. The cutter member 505 has an arm portion 505a and a front portion 505b as a surface portion that forms approximately a "T" shape (see Figure 45).

[0284] The arm portion 505a has a substantially "L" - shaped bent shape with the corner side being the rear - lower side in a left - side view. The arm portion 505a includes a base portion 505c forming the rear side of the side - view shape of the substantially "L" - shape, an intermediate inclined surface portion 505d extending forward and inward in the left - right direction from the lower - end portion 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 on the front side 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 side - view shape of the substantially "L" - shape.

[0285] The arm main body portion 501 includes a main - body rear portion 506 provided at a position shifted outward in the left - right direction with respect to the planting claw 72, and a main - body front portion 507 provided at a position within the width range of the planting claw 72 in the left - right direction. The arm main body portion 501 is a plate - shaped portion with the left - right direction being the plate - thickness direction approximately, and is formed by the support plate 204 and the arm portion 505a of the cutter member 505.

[0286] The cutter member 505 is fixed to the support plate 204 in a state where the upper portion of the base portion 505c is overlapped with the front - end portion of the support plate 204 from the outside. The base portion 505c has a longitudinal shape that is long in the up - down direction, and its rear portion extends downward from the front - end portion of the support plate 204.

[0287] 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 portion of the support plate 204 at the overlapping portion of the base portion 505c of the cutter member 505 and the support plate 204. The bolts 206 penetrate through a hole portion 505f formed in the upper portion of the base portion 505c and are screwed into screw holes formed in the front - end portion of the support plate 204.

[0288] The hole 505f through which the bolt 206 passes is an elongated hole whose longitudinal direction is aligned with the direction in which the cutter member 505 extends from the support plate 204. This allows for adjustment of the fixing position of the cutter member 505 relative to the support plate 204 in the direction of extension.

[0289] Of the main body portion 501 of the arm, the rear portion 506 is the part located outside the planting claws 72 in the left-right direction. Therefore, as shown in Figure 43, the rear portion 506 is formed by the support plate 204, the base portion 505c of the cutter member 505, and the rear portion of the intermediate inclined surface portion 505d.

[0290] Furthermore, of the main body portion 501, the front portion 507 is located within the width range of the planting claws 72 in the left-right direction. Therefore, as shown in Figure 43, the front portion 507 is formed by the front part of the intermediate inclined surface portion 505d of the cutter member 505 and the tip-side arm portion 505e.

[0291] Thus, the main body 501 of the arm shares a common left-right position with respect to the planting claws 72 and the retaining plate 74 and excavating claws 76 located below the planting claws 72 at the front part 507 of the main body, and is provided so as to partially overlap these components in a plan view. Furthermore, the front part 507 of the main body is located below the planting claws 72 and the retaining plate 74.

[0292] The tip-side arm portion 505e of the cutter member 505 is a plate-shaped portion that has a straight line in the front-rear direction when viewed from above, with the left-right direction being the thickness direction, and has a substantially constant width when viewed from the side. The tip-side arm portion 505e is located approximately in the center of the planting claw 72 in the left-right direction. When the groove-making arm 500 is in the groove-making position, the majority of the front side of the tip-side arm portion 505e is positioned in front of the tip of the planting claw 72. Figure 43 shows the state when the groove-making arm 500 is in the groove-making position.

[0293] As described above, the arm body portion 501, which has a rear body portion 506 and a front 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 to the left and right (upward in Figure 43) by the intermediate inclined surface portion 505d, and has a shape in which the tip side arm portion 505e extends forward below the planting claw 72.

[0294] The arm tip portion 502 is provided on the front side of the arm body portion 501. The arm tip portion 502 is located in front of the tip of the excavating claw 76 when the furrowing arm 500 is in the furrowing position (see Figure 42), and is located below the tip of the excavating claw 76 when the furrowing arm 500 is in the standby position (see Figure 44). The arm tip portion 502 is a plate-like portion that protrudes on both the left and right sides from the front arm portion 505e of the cutter member 505 which forms the front part of the arm body portion 501, and is formed by the front portion 505b of the cutter member 505.

[0295] The arm tip 502 is an inclined surface that slopes downward in the direction perpendicular to the claw extension direction when viewed from the side. The arm tip 502 is a plate-like portion that forms a straight line when viewed in cross-sectional section from the side (see Figure 46). Figure 46 is a cross-sectional view of the front part of the groove-making arm 500, and is a left side cross-sectional view of the tip side arm portion 505e at the center position in the left-right direction (plate thickness direction). As shown in Figure 46, the arm tip 502 is a straight line when viewed in cross-sectional section from the side with the extension direction in a predetermined direction (see arrow Z1).

[0296] The arm tip 502 has a lower edge that is a tip projection 502a that protrudes slightly downward relative to the tip of the arm body 501. The arm tip 502 has a downwardly convex mountain shape at its lower edge, with a vertex 502c formed by a pair of slanted edges 502b. The vertex 502c is an obtuse-angled corner formed by the pair of slanted edges 502b.

[0297] With the configuration of the furrowing arm 500 according to this embodiment, the cut width wd1 (see Figure 43) of the mulch film 250 can be made narrower than the cut width wd2 (see Figure 19) of the substantially "U" shaped furrowing arm 200 described above. Here, the cut width wd1 of the furrowing arm 500 is the left-right width dimension of the arm tip portion 502, and the cut width wd2 of the furrowing arm 200 is the left-right dimension between the outer surface portion 205a and the inner surface portion 205c. As a result, when the mulch film 250 is cut by the furrowing arm 500, the width of the cut end of the mulch film 250 can be shortened, and interference of the cut end with the planted seedlings can be suppressed.

[0298] Furthermore, the torn pieces of the mulch film 250 are the remaining pieces of film that remain attached to the main body of the film (in a double-door-like manner) on both the left and right sides of the planted seedlings when the mulch film 250 is cut in a straight line in the front-to-back direction by the arm body portion 501 of the furrowing arm 500. In this respect, with the U-shaped furrowing arm 200, the mulch film 250 is cut in the front-to-back direction by the arm body portion 201 and the auxiliary arm portion 203, so the torn pieces of the mulch film 250 consist of wide remaining pieces with the rear side attached to the main body of the film.

[0299] Furthermore, the T-shaped furrowing arm 500 allows for a smaller amount of soil to be piled up afterward compared to the U-shaped furrowing arm 200, and allows for a relatively larger amount of soil to be used to cover the planted seedlings.

[0300] Furthermore, in the case of the U-shaped furrowing arm 200, since the arm body 201 and the auxiliary arm 203 are positioned to the left and right outward relative to the planting claws 72, the furrowing arm 200 can be brought closer to the planting claws 72. This makes it possible to relatively shorten the cut length (length in the front-to-back direction) of the mulch film 250, and thus shorten the length of the holes in the mulch film 250.

[0301] In contrast, in the case of the T-shaped furrowing arm 500, the front part of the arm body 501 is positioned below the left and right center of the planting claw 72. Therefore, to avoid interference with the components of the planting claw device 50, the furrowing arm 500 is positioned relatively far from the planting claw 72. As a result, the cutting length of the mulch film 250 can be made relatively long, and the length of the holes in the mulch film 250 can be made longer.

[0302] Furthermore, the furrowing arm 500, like the U-shaped furrowing arm 200 described above, is configured so that the arm tip 502 is upright relative to the field surface when it enters the field surface, thereby reducing the furrowing torque and the driving torque of the planting claw device 50. In particular, by aligning the linear extension direction of the arm tip 502 in a side cross-sectional view (see Figure 46, arrow Z1) with the trajectory of the tip projection 502a during the furrowing operation, the furrowing torque and other factors can be effectively reduced. In addition, the arm tip 502 can smoothly cut the mulch film 250, and in particular, the mountain shape at the bottom of the arm tip 502 provides a smooth cutting action on the mulch film 250.

[0303] [Third Embodiment] A third embodiment of the planting unit according to the present invention will be described with reference to Figure 47. The planting unit according to this embodiment differs from the planting unit according to the above-described embodiment in terms of the operation of the furrowing arm, and more specifically in the trajectory traced by the tip of the furrowing arm.

[0304] Figure 47 illustrates a configuration in which the furrowing arm 500 according to the second embodiment is used as the furrowing arm. Figure 47 also shows the movement trajectory of the planting claws 72 and the furrowing arm 500 when the planting unit is in a state where the axis support is spaced apart and the spacing between plants is relatively small, with a plant spacing dimension S2 (for example, 24 cm).

[0305] In this embodiment, regarding the operation of the furrowing arm 500, the furrowing arm 500 is provided such that, as the moving trajectory of its tip, it traces a trajectory E4 including a horizontal trajectory portion around at least a part of the space from which the seedling block 110, held together with the planting claw 72 and the holding plate 74, is pushed out. Trajectory E4 is part of the trajectory W2 of the arm tip 502 of the furrowing arm 500, and is shown as a dashed line in Figure 47. Trajectory E4 shows the trajectory of the top 502c of the arm tip 502.

[0306] In a side view, the furrowing arm 500 moves with respect to the area where the seedling block 110 to be planted in the field is located and the area corresponding to the seedling block, by moving the arm tip 502 from the front of the area corresponding to the seedling block, passing under the area corresponding to the seedling block with a gap, and then wrapping around to the rear. In other words, in the turning point from the downward movement to the upward movement, the furrowing arm 500 moves the arm tip 502 in a manner that makes a U-turn around the area corresponding to the seedling block so that the trajectory E4 does not interfere with the area corresponding to the seedling block.

[0307] According to the furrowing arm 500, soil from the field is removed along the trajectory of the arm tip 502 to create a furrow. The furrowing arm 500 acts on the field so that the portion of the field where soil is removed by the furrowing arm 500 (the furrowed portion) becomes the space where the seedling blocks 110 released from the planting claw device 50 will be located. In the trajectory E4, the area enclosed by the roughly "U" shaped folded portion at the lower end is secured as the release space for the seedling blocks 110 when the furrowing by the furrowing arm 500 is completed.

[0308] As described above, the trajectory E4 of the arm tip 502 has a horizontal section 600, which is a horizontal trajectory portion, around the space for pushing out the seedling block 110. The horizontal section 600 is the portion of the trajectory E4 that follows the field surface 91 in a side view and is a straight portion that follows the front-rear direction of the machine (left-right direction in Figure 47). The horizontal section 600 forms the lower end (bottom) of the folded portion at the bottom of the trajectory E4. Therefore, the horizontal section 600 represents the path of movement of the arm tip 502, moving horizontally from front to rear below the portion corresponding to the seedling block.

[0309] Thus, the trajectory E4 having the horizontal section 600 has a lower folded-over section that is a trajectory section in which the lower fold-over section consists of a descending trajectory section 601 that shows the descending movement of the arm tip 502, and an ascending trajectory section 602 that shows the ascending movement of the horizontal section 600 and the horizontal section 600 are continuous. The descending trajectory section 601 has a convex bulge shape on the front side and its lower end is connected to the front side of the horizontal section 600. The ascending trajectory section 602 has its lower end connected to the rear side of the horizontal section 600 and has a slightly forward-sloping, substantially straight shape.

[0310] The trajectory E4 of the arm tip 502 described above is obtained by adjusting the shape of the cam surface 411 (see Figure 23) of the cam plate 410 so that the trajectory portion at the lower end of the trajectory E4 approaches horizontal.

[0311] According to trajectory E4, the furrowing arm 500 performs a downward trajectory 601 on the field surface 91 by inserting its arm tip 502 from a position in front of the virtually placed seedling block 110. Subsequently, the arm tip 502 moves to the underside of the virtually placed seedling block 110 and performs a horizontal movement 600 by moving the arm tip 502 horizontally from front to back. Then, at the moment the arm tip 502 reaches the rear side of the virtually placed seedling block 110, the seedling block 110 is pushed out by the pressing piece 87 and actually planted.

[0312] The furrowing arm 500, with its tip (top 502c) positioned below and behind the planted seedling block 110, moves its arm tip 502 upwards as it traces an upward trajectory 602, and moves away from the field surface 91. Subsequently, the furrowing arm 500 moves its arm tip 502 upwards and slowly moves towards the front of the seedling block 110 above the seedling block 110.

[0313] According to the operation of the furrowing arm 500 in this embodiment, when the seedling blocks 110 are released into the field, a horizontal seedling receiving portion is formed in the field as the bottom surface of the furrow created by the furrowing arm 500. As a result, the released seedling blocks 110 are planted in an upright position, following the relatively hard, horizontal furrow bottom formed by the furrowing arm 500. Therefore, a good upright planting position can be obtained for the seedlings.

[0314] [Fourth Embodiment] A fourth embodiment of the planting unit according to the present invention will be described with reference to Figure 48. The planting unit according to this embodiment differs from the planting unit according to the above-described embodiment in terms of the configuration of the pressing piece 87 of the extrusion member 73.

[0315] As shown in Figure 48, in this embodiment, the pressing piece 87 has a pressing surface 87e, which acts on the seedling block 110, that is inclined in a side view with respect to the extrusion direction by the pressing piece 87. The extrusion direction by the pressing piece 87 is the claw extension direction (see arrow C1), which is the direction along which the upper surface 82b of the claw body portion 82 follows in a side view. The pressing surface 87e is a plane that follows a straight line in a side view.

[0316] In the embodiment described above, the pressing surface 87e of the pressing piece 87 is aligned in a plane direction perpendicular to the nail extension direction in a side view (hereinafter referred to as the "vertical plane direction") (see Figure 12, etc.). In contrast, in this embodiment, as shown in Figure 48, the pressing surface 87e of the pressing piece 87 is inclined in a direction that is forward-sloping with respect to the vertical plane direction indicated by the dashed line K1 in a side view. In other words, in a side view, the pressing surface 87e is inclined in a direction that positions the upper side towards the front of the nail extension direction and the lower side towards the rear of the nail extension direction with respect to the vertical plane direction.

[0317] Regarding the degree of inclination of the pressing surface 87e, in a side view, the inclination angle γ1 of the pressing surface 87e with respect to the vertical plane is, for example, within the range of 10 to 30° (for example, about 20°). The magnitude of the inclination angle γ1 for the pressing surface 87e is not particularly limited.

[0318] According to the configuration of the pressing piece 87 in this embodiment, the inclination of the pressing surface 87e allows for correction of the posture of the seedling block 110 pushed out by the pressing piece 87. This makes it easier to ensure that the seedling block 110 remains upright in the soil of the field, and a good upright planting posture can be obtained for the seedlings. By combining the configuration of the pressing piece 87 in this embodiment with the operating mode of the furrowing arm 500 in the third embodiment, the seedling block 110 can be planted upright effectively, and a good planting posture can be obtained.

[0319] As described above using embodiments, the seedling transplanter according to the present invention is not limited to the embodiments described above, and various forms can be adopted within the scope consistent with the spirit of the present invention.

[0320] This technology can take the following configurations. Note that the configurations described below can be selected and combined as desired. (1) This seedling transplanter continuously plants seedlings in the field by cutting off sections of a seedling mat placed on a seedling tray using planting claws. The planting claw is provided near the planting claw and is provided to move relative to the planting claw, The furrowing arm has two relative positions to the planting claws: a waiting position which is the position when the planting claws cut the seedling mat, and a furrowing position which is when the arm is moved forward relative to the planting claws when planting seedlings in the field. A seedling transplanter characterized by the following features. (2) The furrowing arm is designed to perform a cyclical movement, returning from the furrowing position to the standby position after the planting of seedlings in the field by the planting claws is completed. The seedling transplanter according to (1) above, characterized in that (3) The furrowing arm is positioned such that, when in the furrowing position, its tip protrudes forward of the planting claws and enters the field surface before the planting claws. The seedling transplanter according to (1) or (2) above, characterized in that (4) The furrowing arm is designed so as not to interfere with seedlings planted in the field, at least within the range of motion where its tip is positioned below the field surface. A seedling transplanter according to any one of (1) to (3) above, characterized in that it is the same as described above. (5) The furrowing arm is provided to change its position and orientation in conjunction with the movement of the planting claws. A seedling transplanter according to any one of (1) to (4) above, characterized in that it is the same as described above. (6) The groove-making arm is provided with a rotary case that rotatably supports the planting claw device including the planting claws, and a cam mechanism including a cam changes the relative position of the groove-making arm with respect to the planting claws as the planting claw device rotates, thereby changing its position and orientation in conjunction with the movement of the planting claws. The seedling transplanter according to (5) above, characterized in that (7) The furrowing arm has a plate-like portion at its tip that forms a straight line when viewed in side cross-section, and is designed so that the plate-like portion stands upright relative to the field surface when it enters the field surface. A seedling transplanter according to any one of (1) to (6) above, characterized in that it is the same as described above. (8) The groove-making arm is positioned such that its tip traces a path that secures space for pushing out the seedling held by the planting claw located at its lowest end. A seedling transplanter according to any one of (1) to (7) above, characterized in that it is the same as described above. (9) The furrowing arm comprises an arm body positioned to one side in the left-right direction relative to the planting claw, and an arm tip positioned at the tip of the arm body. A seedling transplanter according to any one of (1) to (8) above, characterized in that (10) The tip of the arm is the part that is connected to the main body of the arm at one end in the left-right direction. The groove-making arm is positioned offset to the other side in the left-right direction from the planting claw, and has an auxiliary arm portion with one end connected to the other end in the left-right direction of the tip of the arm. The seedling transplanter according to (9) above, characterized in that (11) The groove-making arm includes an arm body portion which includes a portion located offset to one side in the left-right direction relative to the planting claw, and a portion located within the width range of the planting claw in the left-right direction, and an arm tip portion located at the tip side of the arm body portion. A seedling transplanter according to any one of (1) to (8) above, characterized in that (12) The tip of the arm is a portion that protrudes to the left and right from the main body of the arm. The seedling transplanter according to (11) above, characterized in that (13) The groove-making arm is provided so as to trace a trajectory at its tip that includes a horizontal trajectory portion in at least a part of the space around which the seedling held by the planting claw is pushed out. A seedling transplanter according to any one of (1) to (12) above, characterized in that it is the same as described above. [Explanation of Symbols]

[0321] 1 Seedling transplanter 3 Seedling transplant device 42 Seedling stand 50 Planted nail device 52 Rotary Case 72 Planting claws 91 Field scene 100 seedling mats 110 seedling blocks 200 groove-making arm 201 Arm body 202 Arm tip 203 Auxiliary arm section 270 Trajectory changing device 300 Link Mechanism 301 Front arm (link arm) 302 Rear arm (link arm) 313 Front moving axis support 314 Rear moving axis support 400 Cam mechanism 410 Cam Plate (Cam) 500 groove-making arm 501 Arm body 502 Arm tip 506 Rear of the main unit 507 Front of the main unit

Claims

1. This seedling transplanter continuously plants seedlings in the field by cutting off sections of a seedling mat placed on a seedling tray using planting claws. The planting claw is provided near the planting claw and is provided to move relative to the planting claw, The tip of the groove-making arm has a downwardly convex mountain shape, with a pair of slanted edges forming its apex at its lower edge. The furrowing arm is positioned so as to enter the field surface ahead of the planting claws, with its top portion protruding forward of the planting claws. A seedling transplanter characterized by the following features.

2. The furrowing arm has a relative position to the planting claws, which is the waiting position at the time when the planting claws cut the seedling mat, and a furrowing position when it is moved forward relative to the planting claws when planting seedlings in the field. The seedling transplanter according to feature 1.

3. The furrowing arm is designed so as not to interfere with seedlings planted in the field, at least within the range of motion where its tip is positioned below the field surface. A seedling transplanter according to claim 1 or 2.

4. The furrowing arm is provided to change its position and orientation in conjunction with the movement of the planting claws. The seedling transplanter according to feature 2.

5. The groove-making arm is provided with a rotary case that rotatably supports the planting claw device including the planting claws, and a cam mechanism including a cam changes the relative position of the groove-making arm with respect to the planting claws as the planting claw device rotates, thereby changing its position and orientation in conjunction with the movement of the planting claws. The seedling transplanter according to feature 4.

6. The furrowing arm has a plate-like portion at its tip that forms a straight line when viewed in side cross-section, and is designed so that the plate-like portion stands upright relative to the field surface when it enters the field surface. A seedling transplanter according to claim 1 or 2.

7. The groove-making arm is positioned such that its tip traces a path that secures space for pushing out the seedling held by the planting claw located at its lowest end. A seedling transplanter according to claim 1 or 2.

8. The furrowing arm comprises an arm body positioned to one side in the left-right direction relative to the planting claw, and an arm tip positioned at the tip of the arm body. A seedling transplanter according to claim 1 or 2.

9. The tip of the arm is the part that is connected to the main body of the arm at one end in the left-right direction. The groove-making arm is positioned offset to the other side in the left-right direction from the planting claw, and has an auxiliary arm portion with one end connected to the other end in the left-right direction of the tip of the arm. The seedling transplanter according to feature 8.

10. The groove-making arm includes an arm body portion which includes a portion located offset to one side in the left-right direction relative to the planting claw, and a portion located within the width range of the planting claw in the left-right direction, and an arm tip portion located at the tip side of the arm body portion. A seedling transplanter according to claim 1 or 2.

11. The tip of the arm is a portion that protrudes to the left and right from the main body of the arm. The seedling transplanter according to feature 10.

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