[0001] The present invention relates to a field work machine that includes a
plurality of seedling planting mechanisms capable of planting seedlings in a
field.
10
Background Art
[0002] For example, Patent Document 1 discloses a seedling planting mechanism (“seedling planting apparatus” in the document) for ridable rice transplanters. Planting arms (“planting claw support cases” in the document)
15 of the seedling planting mechanisms that are capable of planting seedlings in a field each have, inside thereof, a storage space (“driving system interior space” in the document) that can be filled with a lubricant agent. The planting arm is provided with a grease nipple and a plug, and the plug is screwed into an opening/closing portion of a case of the planting arm that is open to the outside
20 from the planting arm.
Prior Art Document
Patent Document
[0003] Patent Document 1: JP 2015-173663A
25
Disclosure of the Invention
Problem to be Solved by the Invention
[0004] When an operator pours a lubricant agent from the grease nipple, the
operator typically opens the plug, and pours the lubricant agent from the
30 opening/closing portion of the planting arm while checking the level of the lubricant agent in the storage space. However, a ridable rice transplanter includes a plurality of such seedling planting mechanisms, and thus if the plugs of the plurality of seedling planting mechanisms are attached and removed, maintenance of the plugs and the entire planting arms will be bothersome.
35 [0005] In order to avoid such a disadvantage, in Patent Document 1, when an operator pours a lubricant agent from the grease nipple, the lubricant agent will leak from a small gap in the portion where the opening/closing portion and
2

the plug are screwed together in accordance with an increase in the internal pressure of the storage space in the planting arm. This avoids the risk that the storage space of the planting arm is excessively filled with the lubricant agent. However, according to Patent Document 1, there is no partition 5 member (“seal material” in the document) between the opening/closing portion and the plug of the case of the planting arm. In this configuration, there is always an oil film of the lubricant agent in the portion where the opening/closing portion and the plug are screwed together, and thus, in order to prevent the plug from loosening due to the oil film, the plug needs to be further
10 tightened in the opening/closing portion with an appreciable tightening torque. Thus, the operator needs to pay appreciable attention to the maintenance of the plug. On the other hand, the plug functions to release the lubricant agent stored in the storage space to the outside, and a configuration in which this function is fulfilled by another member of the planting arm for another purpose
15 will achieve an advantage in terms of cost, and improve the ease of maintenance.
[0006] It is an object of the present invention to provide a field work machine that includes seedling planting mechanisms that allow easy maintenance of a lubricant agent.
20
Means for Solving Problem
[0007] According to the present invention, a field work machine includes a plurality of seedling planting mechanisms capable of planting seedlings in a field, wherein each of the seedling planting mechanisms includes: a storage
25 space capable of storing a lubricant; a partition member that is provided in a gap of the storage space that is open to an outside of the seedling planting mechanism, and is capable of preventing the lubricant agent from leaking from the storage space; and a release part capable of releasing the lubricant agent from the gap to the outside of the seedling planting mechanism via the
30 partition member.
[0008] According to the present invention, the field work machine has a configuration in which the gap that is open to the outside of the seedling planting mechanism is filled with the partition member, and at the same time, a lubricant agent can escape to the outside of the seedling planting mechanism
35 from the partition member via the release part. With this, it is possible to switch between a state in which the lubricant agent does not leak from the partition member as needed, and a state in which the lubricant agent is
3

released from the partition member via the release part as needed, according to a combination of the partition member and the release part. Therefore, there is no need of detaching the partition member and the like when feeding the lubricant agent, and thus the ease of maintenance of the seedling planting 5 mechanism is improved. With this, a field work machine that includes seedling planting mechanisms that allow the easy maintenance of a lubricant agent can be realized.
[0009] In the present invention, preferably, the field work machine further comprising a supply port for allowing the lubricant to be supplied to the storage
10 space is provided, wherein the partition member is configured to guide the lubricant agent to the release part when the lubricant agent is supplied from the supply port and is compressed.
[0010] With this configuration, if the storage space is excessively filled with the lubricant agent, a configuration is adopted in which the lubricant agent can be
15 guided to the release part by the partition member, thus advantageously avoiding the risk that the storage space is excessively filled with the lubricant agent.
[0011] In the present invention, preferably, the seedling planting mechanism includes: a rotation case that has a rotation axis at a central portion in a
20 longitudinal direction thereof, and is rotatable around the axis oriented in a lateral direction of a machine body; and a planting arm that is provided at an end portion of the rotation case in the longitudinal direction, and capable of planting seedlings in a field, and the gap in a form of a coupling part in which the rotation case and the planting arm are coupled to each other.
25 [0012] With this configuration, the coupling portion in which the rotation case and the planting arm are coupled to each other is a gap, and thus the release part is provided in the gap of the coupling portion. That is to say, since the coupling portion of the rotation case and the planting arm is also used as the release part, an advantage in terms of cost can be achieved.
30 [0013] In the present invention, preferably, the coupling part has a spigot joint structure in which the rotation case and the planting arm are engaged with each other, and the release part is in a form of a surface-treated notch in either or both of the rotation case and the planting arm of the spigot joint structure. [0014] With this configuration, the coupling portion of the rotation case and
35 the planting arm has a configuration in which they are engaged with each other by a spigot joint structure, and thus the accuracy in assembling the rotation case and the planting arm in the coupling portion is improved. Furthermore,
4

since this spigot joint structure includes a portion that is surface-treated in the shape of a notch, and this portion that is surface-treated in the shape of a notch is used as the release part, a configuration can be adopted in which when a lubricant agent is released to the outside of the seedling planting mechanism, 5 the lubricant agent actively escapes from the portion that is surface-treated in the shape of a notch. Also, with this configuration, the path through which the lubricant agent escapes to the outside of the seedling planting mechanism is limited to this release part in the shape of a notch, and thus it is possible to easily realize a configuration in which the partition member stops the lubricant
10 agent on the way to the release part in the shape of a notch, as needed. With this, the ease of maintenance of the release part is improved. [0015] In the present invention, preferably, the release part is located above a central portion of the coupling part in a vertical direction. [0016] Because the seedling planting mechanism is often located on the lower
15 side relative to the point of view of an operator, this configuration can allow the operator to easily check the lubricant agent that is released to the outside of the storage space from the release part.
[0017] In the present invention, preferably, in the coupling part, the rotation case and the planting arm are coupled to each other with a coupling bolt, and
20 the release part is located on a side of the coupling part opposite to a side on which the coupling bolt is located.
[0018] With the present embodiment, the release part is located on a side of the coupling portion opposite to a side on which the coupling bolt is located, reducing the risk that the lubricant agent is attached to the coupling bolt.
25 This significantly reduces the risk that the coupling bolt slackens due to the friction reducing effect of the lubricant agent.
[0019] In the present invention, preferably, the partition member and the release part are provided on the rotation case. [0020] With this configuration, it is easy to fill the rotation case with the
30 lubricant agent.
[0021] In the present invention, preferably, the partition member and the release part are provided on the planting arm.
[0022] With this configuration, it is easy to fill the planting arm with the lubricant agent.
35 [0023] In the present invention, the lubricant agent is preferably lubricant oil. Also, the lubricant agent is preferably lubricant oil. Furthermore, preferably, the lubricant agent for the rotation case is lubricant oil, and the lubricant agent
5

for the planting arm is grease.
[0024] Grease and lubricant oil often have different viscosities. With this configuration, it is possible to select a lubricant agent that has a suitable viscosity according to the rotation case or the planting arm to which it is 5 applied.
[0025] In the present invention, preferably, the partition member is an oil seal. [0026] With this configuration, the partition member can prevent the lubricant agent from leaking from the storage space, and can guide the lubricant agent to the release part, as needed. 10
Brief Description of the Drawings
[0027] FIG. 1 is a side view illustrating an overall rice transplanter.
FIG. 2 is a plan view illustrating the overall rice transplanter.
FIG. 3 is a transverse cross-sectional view of a rotation case and 15 planting arms.
FIG. 4 is a longitudinal cross-sectional view illustrating the rotation case.
FIG. 5 is a longitudinal cross-sectional view illustrating the planting
arm.
20 FIG. 6 is a cross-sectional view illustrating a coupling portion where the
rotation case and the planting arm are coupled to each other, when viewed in a front-back direction of the machine body.
FIG. 7 is a cross-sectional view taken along a line VII-VII in FIG. 6, illustrating the coupling portion where the rotation case and the planting arm 25 are coupled to each other.
FIG. 8 is a cross-sectional view illustrating a release part in the coupling portion where the rotation case and the planting arm are coupled to each other, when viewed in the front-back direction of the machine body.
FIG. 9 is a transverse cross-sectional view of a rotation case and 30 planting arms according to another embodiment.
Best Mode for Carrying out the Invention
[0028] [Basic Configuration of Field Work Machine]
The following will describe embodiments of the present invention with
35 reference to the drawings. Here, a description is given taking a ridable rice
transplanter as an example of the field work machine of the present invention.
Note that as shown in FIGS. 1 and 2, in the present embodiments, an arrow (F)
6

indicates the machine front side of a traveling machine body 1, an arrow (B) indicates the machine back side of the traveling machine body 1, an arrow (L) indicates the machine left side of the traveling machine body 1, and an arrow (R) indicates the machine right side of the traveling machine body 1. 5 [0029] The ridable rice transplanter includes the traveling machine body 1 that has a left and right pair of wheels 2 for steerage and a left and right pair of rear wheels 3, and a seedling planting apparatus W of eight-row planting type, the seedling planting apparatus W serving as a work apparatus capable of planting seedlings in a field. The left and right pair of wheels 2 for steerage is
10 provided on the machine front side of the traveling machine body 1 and is configured to freely steer and change the orientation of the traveling machine body 1. The left and right pair of rear wheels 3 is provided on the machine back side of the traveling machine body 1. The seedling planting apparatus W is coupled to a back end of the traveling machine body 1 via a link mechanism 5
15 so as to be liftable, the link mechanism 5 being configured to be lifted and lowered by expansion and contraction of a hydraulic lift cylinder 4. [0030] An openable bonnet 6 is provided in a front portion of the traveling machine body 1. The bonnet 6 includes, at a front-end position thereof, a rod-shaped center mascot 7, which serves as an indicator used for the field work
20 machine to travel along a marked line (not shown) drawn on the field by a marker (not shown). The traveling machine body 1 includes a machine frame 1F that extends in the front-back direction, and a support column frame 8 stands upright from a front portion of the machine frame 1F. [0031] An engine E is provided inside the bonnet 6. Although not described in
25 detail, power of the engine E is transmitted to the wheels 2 for steerage and the rear wheels 3 via a gear shifter provided in the machine body, and power after gear shifting is transmitted to the seedling planting apparatus W via an electric motor-driven planting clutch (not shown). [0032] The seedling planting apparatus W of eight-row planting type includes
30 four power transmission case 10, eight seedling planting mechanisms 11, land-leveling floats 12, a seedling pedestal 13, and land-leveling rotors 14. The seedling planting mechanisms 11 are supported on left-side and right-side portions of a rear portion of each of the power transmission cases 10 so as to be rotatable. Each of the seedling planting mechanism 11 includes a rotation
35 case 11A and planting arms 11B. The pair of rotary-type planting arms 11B are provided on both end portions of each rotation case 11A. The planting arms 11B are each configured to be able to plant seedlings in a field. The
7

land-leveling floats 12 comes into contact with and follows a rice field plane of the field to level the rice field plane. The seedling planting apparatus W includes a plurality of such land-leveling floats 12. A mat-shaped seedlings to be planted are placed on the seedling pedestal 13. 5 [0033] The seedling planting apparatus W drives the seedling pedestal 13 so that it transversely reciprocates left and right, and drives and rotates the rotation cases 11A using the power transmitted from the power transmission cases 10 so that seedlings are taken alternately by the planting arms 11B from the lower portion of the seedling pedestal 13 and are planted in the rice field
10 plane of the field. The seedling planting mechanisms 11 are configured to plant seedlings using the planting arms 11B provided on the plurality of rotation cases 11A. When four seedling planting mechanisms 11 are provided, the seedling planting apparatus W is of four-row planting type, when six seedling planting mechanisms 11 are provided, the seedling planting apparatus
15 W is of six-row planting type, when eight seedling planting mechanisms 11 are provided, the seedling planting apparatus W is of eight-row planting type, and when ten seedling planting mechanisms 11 are provided, the seedling planting apparatus W is of ten-row planting type. [0034] Two auxiliary seeding pedestals 16 are provided on the left-side and
20 right-side portions of the bonnet 6 of the traveling machine body 1. The auxiliary seeding pedestals 16 have a rail structure on which auxiliary seedings for refilling the seedling planting apparatus W can be placed. The bonnet 6 of the traveling machine body 1 is provided with, in the left-side and right-side portions thereof, a left and right pair of auxiliary seeding frames 17 that serve
25 as tall frame members for supporting the auxiliary seeding pedestals 16. Upper portions of the left and right auxiliary seeding frames 17 are coupled to each other by a coupling frame 18.
[0035] The traveling machine body 1 includes, in a central portion thereof, a boarding part 20 in which various types of driving operations are performed.
30 The boarding part 20 includes a driving seat 21, a steering handle 22, a main gear lever 23, and an operation lever 24. The driving seat 21 is provided in the central portion of the traveling machine body 1, and is configured such that a driver can seat thereon. The steering handle 22 is configured to be able to steer the wheels 2 for steerage in accordance with a human operation. The
35 main gear lever 23 is configured to be able to perform switching operation between forward movement and rearward movement, and perform an operation for changing the traveling speed. The operation lever 24 is used to perform
8

operations of lifting the seedling planting apparatus W and switching between left and right land-leveling rotors 14. The steering handle 22, the main gear lever 23, the operation lever 24, and so on are provided in an upper portion of a control tower 25 located in front of the driving seat 21 with respect to the 5 machine body. The boarding part 20 includes, on both left and right side of a foot region thereof, boarding/alighting steps 26 used for a driver to board on and alight from the boarding part 20 on lateral sides of the machine body. [0036] When the operation lever 24 is operated to a lift position, the planting clutch (not shown) is turned off to interrupt the transmission of power to the
10 seedling planting apparatus W, and the hydraulic lift cylinder 4 is activated to lift the seedling planting apparatus W. When the operation lever 24 is operated to a lowering position, the seedling planting apparatus W is lowered, comes into contact with a rice field plane, and is then stopped. [0037] When starting a rice planting operation, the driver operates the
15 operation lever 24 so as to lower the seedling planting apparatus W, and starts the transmission of power to the seedling planting apparatus W, thereby starting the rice planting operation. Also, when stopping the rice planting operation, the driver operates the operation lever 24 so as to lift the seedling planting apparatus W, and interrupts the transmission of power to the seedling
20 planting apparatus W.
[0038] [Regarding Seedling Planting Mechanism]
As shown in FIGS. 3 and 4, a drive shaft 30 is provided extending from the power transmission case 10 to the rotation cases 11A, and the drive shaft 30 is configured to be able to rotate around a lateral axis P1 extending in a lateral
25 direction of the machine body. The drive shaft 30 protrudes to the left and right sides of the machine body relative to the power transmission case 10, and the rotation cases 11A are coupled to left and right-end portions of the drive shaft 30 so as to be rotatable together with the drive shaft 30. That is to say, a locking pin 31 is interposed between an outer circumferential portion of a
30 leading end of the drive shaft 30 and the corresponding rotation case 11A, and the drive shaft 30 and the rotation case 11A are configured to be unable to rotate relative to each other due to the locking pin 31. Accordingly, the rotation case 11A has the rotation axis at its central portion in the longitudinal direction, and is configured to be able to rotate around the lateral axis P1
35 extending in the lateral direction of the machine body.
[0039] Tubular members 32 are respectively fixed with bolts to left and right end portions of each power transmission case 10. The tubular members 32 are
9

externally fitted to the drive shaft 30, and are internally fitted to the respective rotation cases 11A. A claw portion 32a is formed at an end of each tubular member 32 that is opposite to the end on the side on which the power transmission case 10 is located. Inside each rotation case 11A, an axis gear 33 5 is externally fitted to the drive shaft 30, and engages with the claw portion 32a. With this configuration, the axis gear 33 is fixed so as not to be able to rotate relative to the power transmission case 10 while being located inside the rotation case 11A. The drive shaft 30 is configured to be able to rotate relative to the tubular member 32 and the axis gear 33 while being internally fitted to
10 the tubular member 32 and the axis gear 33. With this, even when the drive shaft 30 is rotated around the lateral axis P1, the axis gear 33 remains unmoved. Also, since the drive shaft 30 and the rotation case 11A are rotated together, even when the rotation case 11A are rotated around the lateral axis P1, the axis gear 33 remains unmoved at the position of the lateral axis P1.
15 [0040] Planting gears 35 are provided in the respective end portions of the rotation case 11A in the longitudinal direction. Also, intermediate gears 34 are provided between the axis gear 33 and the planting gears 35 in the rotation case 11A. Each of the intermediate gears 34 engages with the axis gear 33. Also, each of the intermediate gears 34 engages with the planting gear 35
20 located on the side opposite to the side on which the axis gear 33 is located. The respective planting gears 35 are externally fitted to support shafts 35A, and the planting gear 35 and the support shaft 35A are engaged with each other by a spline structure so as not to be able to rotate relative to each other. Each support shaft 35A protrudes laterally outward from the rotation case 11A,
25 and a coupling flange surface 35B is formed on the protruding end portion of the support shaft 35A. Also, the coupling flange surface 35B of the support shaft 35A and a coupling surface 11C of the planting arm 11B are coupled to each other with a coupling bolt Bo so as not to be able to rotate relative to each other. The coupling part in which the coupling flange surface 35B of the
30 rotation case 11A and the coupling surface 11C of the planting arm 11B are coupled to each other with the coupling bolt Bo is hereinafter referred to as “coupling portion C”. That is to say, as a result of the rotation case 11A and the planting arm 11B being coupled to each other with the coupling bolt Bo at the coupling portion C, the planting gear 35 and the planting arm 11B are
35 configured to be able to rotate around a lateral axis P2 at each of the two end portions of the rotation case 11A in the longitudinal direction. Note that the pair of lateral axes P2 are symmetric with respect to the lateral axis P1, and
10

are parallel to the lateral axis P1.
[0041] Although not described in details, the axis gear 33, the intermediate gears 34, and the planting gears 35 are each configured as an eccentric gear (or noncircular gear), and the rotational speeds of the planting gears 35 and the 5 planting arms 11B increase/decrease periodically in accordance with the rotational angle of the axis gear 33. As shown in FIG. 4, when the rotation case 11A is driven to rotate around the lateral axis P1 in a counterclockwise direction of the paper plane of FIG. 4, that is, the direction indicated by arrows B1, the intermediate gears 34, the planting gears 35, and the planting arms
10 11B revolve around the fixed axis gear 33. At the same time, as a result of the axis gear 33 and the intermediate gears 34 engaging with each other, the intermediate gears 34 rotate in the direction indicated by arrows B2. In addition, as a result of the intermediate gears 34 and the planting gears 35 engaging with each other, the planting gears 35 rotate, together with the
15 planting arms 11B, in the direction indicated by arrows B3. Accordingly, as shown in FIG. 4, the planting arms 11B are driven to rotate while drawing a rotational trajectory F, and the planting arms 11B take out seedlings from the seedling pedestal 13. At this time, the taken seedlings are held by a planting claw 42. Also, the planting arms 11B protrude into a rice field plane to plant
20 the seedlings in the rice field plane.
[0042] A rotation operation body 36 is externally fitted to a position, of each support shaft 35A, adjacent to the corresponding planting gear 35 in the lateral direction of the machine body, and the rotation operation body 36 and the support shaft 35A are coupled to each other by a spline structure so as not to be
25 able to rotate relative to each other. That is to say, the rotation operation body
36 is configured to rotate together with the support shaft 35A around the
lateral axis P2. The rotation operation body 36 is formed in an ellipsoidal
shape centered at the lateral axis P2.
A pair of projections are formed along a long-diameter direction of an 30 ellipse of the rotation operation body 36, and the respective projections expand symmetrically with respect to the lateral axis P2. [0043] Arms 37 are provided inside the rotation case 11A, and each of the arms
37 is supported so as to be rotatable around a lateral axis P3 extending in the
lateral direction of the machine body while abutting against an outer
35 circumferential portion of the corresponding rotation operation body 36. Note that the pair of lateral axes P3 are symmetric with respect to the lateral axis P1, and are parallel to the lateral axis P1. A coil-shaped spring 38 is provided
11

extending from each arm 37 to a wall portion of the rotation case 11A, and the spring 38 is provided while being compressed in the longitudinal direction. With this, the arm 37 is biased so as to push against the outer circumferential portion of the rotation operation body 36. 5 [0044] The wall portion of the rotation case 11A is recessed at positions at which the springs 38 are received, and an oil supply port 11o is provided in at least one of the recessed portions. The oil supply port 11o is a supply port from which a lubricant agent can be supplied into a storage space S1. The rotation case 11A is configured to be able to be filled with lubricant oil from the oil
10 supply port 11o. The inside of the rotation case 11A is formed as the storage space S1 for lubricant oil, and the rotation case 11A is filled with the lubricant oil.
[0045] A description on a planting arm 11B will be given below. As shown in FIG. 5, the planting arm 11B includes a lower case 40 and an upper case 41,
15 and the lower case 40 and the upper case 41 are coupled to each other with a bolt. The planting claw 42 is coupled to a portion of the lower case 40 on the side opposite to the upper case 41, and the planting claw 42 protrudes downward relative to the lower case 40. The lower portion of the lower case 40 is tubular extending in a vertical direction, and a tubular bush 43 is internally
20 fitted to the inner tubular portion of this tubular portion. Also, a columnar rod 44 is internally fitted to the inner tubular portion of the bush 43, and the rod 44 is configured to be able to slide in the longitudinal direction of the planting claw 42. A lower end portion of the rod 44 protrudes downward from the lower case 40, and a seedling pushing tool 49 is supported on this lower end portion. The
25 seedling pushing tool 49 is in sliding contact with the planting claw 42, and is configured to be able to slide together with the rod 44 in the longitudinal direction of the planting claw 42.
[0046] Note that an oil seal or a rubber gasket is provided at a position located on the lower side (side on which the lower end portion of the rod 44 is located)
30 of the lower case 40 relative to the bush 43. That is to say, the lower case 40 has a configuration such that even when the rod 44 slides, grease stored inside the planting arm 11B is received by the oil seal or the rubber gasket, and the grease is prevented from leaking to the outside of the planting arm 11B. [0047] As shown in FIG. 5, a flange-shaped spring support part 45 is coupled to
35 an upper end portion of the rod 44, and a lower end portion of a coil-shaped spring 46 is supported by the spring support part 45. The spring 46 extends in the vertical direction, and an upper end portion of the spring 46 is supported on
12

the inner wall of an upper end portion of the upper case 41. The spring 46 is biased so as to push the rod 44 downward.
[0048] An upper portion of the rod 44 is continuously connected to an operation arm 47 via a link member 48. The operation arm 47 is L-shaped when viewed 5 from a side, and the L-shaped bent portion of the operation arm 47 is supported by an axis pin 47A so as to be swingable.
[0049] As shown in FIGS. 3 to 5, a cam shaft 50 is supported on the lower case 40 so as to be rotatable, and is configured to be able to rotate around the lateral axis P2. Note that the cam shaft 50 and the support shaft 35A are separate
10 and different shafts. A cam part 50a is formed over about a half of the outer circumferential surface of the cam shaft 50, and a base portion 47b of the operation arm 47 and the cam part 50a are in sliding contact with each other. The cam part 50a has a portion whose diameter increases toward the side in the clockwise direction along the circumferential direction.
15 [0050] As shown in FIGS. 3 to 5, the pair of planting arms 11B are respectively provided at two end portions of the rotation case 11A with the lateral axis P1 interposed therebetween, and a linkage member 51 is coupled between the pair of cam shafts 50. That is to say, the pair of cam shafts 50 and the linkage member 51 are configured as one piece, and the cam shafts 50 cannot rotate
20 relative to the linkage member 51. When the rotation case 11A is rotated, the linkage member 51 rotates around the lateral axis P1 at the same rotational speed as that of the rotation case 11A. Also, when the linkage member 51 is rotated, the pair of cam shafts 50 revolve around the lateral axis P1 and rotate around the lateral axis P2. Accordingly, when the rotation case 11A is driven
25 to rotate in the counterclockwise direction of the paper plane of FIG. 4, the planting arms 11B revolve around the lateral axis P1 and rotate clockwise with respect to the rotation case 11A on the paper plane of FIG. 4. [0051] On the paper plane of FIG. 5, the cam part 50a of the cam shaft 50 rotates counterclockwise. With this, when the base portion 47b of the
30 operation arm 47 runs on the cam part 50a of the cam shaft 50, the operation arm 47 turns clockwise on the paper plane of FIG. 5, and the rod 44 slides upward against the spring 46. In this state, the planting arm 11B comes close to the lower end of the seedling pedestal 13, and seedlings are held by the planting claw 42.
35 [0052] In the state in which the rod 44 slides upward against the spring 46, the arms 37 are pushed against the rotation operation body 36 by the biasing force of the spring 38 inside the rotation case 11A. The portion of the rotation
13

operation body 36 that is located beyond the projection in the long-diameter direction abuts against the arm 37, and the biasing force of the spring 38 is gradually released. Accordingly, the biasing force of the spring 46 is cancelled out by the biasing force of the spring 38, and the rotation case 11A can smoothly 5 rotate. That is to say, the activation timings of the rotation operation body 36, the arm 37, and the spring 38 are coordinated so that the biasing force of the spring 38 is exerted as an acting force for causing the seedling pushing tool 49 to move in and out against the spring 46. [0053] When the planting arm 11B protrudes into the rice field plane, the cam
10 part 50a of the cam shaft 50 turns to a side opposite to a side on which the base portion 47b of the operation arm 47 is located. Accordingly, the base portion 47b is disengaged from the cam part 50a, and the rod 44 slides downward due to the biasing force of the spring 46. Also, seedlings are pushed downward from the planting claw 42 by the seedling pushing tool 49, and are planted in
15 the rice field plane. Here, the operation arm 47 turns counterclockwise on the paper plane of FIG. 5, and the operation arm 47 is received by a rubber body 54. The rubber body 54 is fixed to the lower case 40. When the operation arm 47 turns counterclockwise on the paper plane of FIG. 5 due to the rod 44 being pushed downward, the operation arm 47 is received by the rubber body 54 and
20 the impact of the rod 44 and the operation arm 47 is absorbed.
[0054] As shown in FIG. 5, an opening is formed in the upper end portion of the upper case 41, and a nut 52 is inserted into this opening. An upper end portion of the nut 52 is exposed to the outside of the upper case 41. Then, a grease nipple 53 is attached to the nut 52. When a grease gun (not shown) is
25 connected to the grease nipple 53, it is possible to pour the grease into the planting arm 11B. The inside of the planting arm 11B is formed as a storage space S2 for grease, and the planting arm 11B is filled with the grease. That is to say, the inside of the planting arm 11B is the storage space S2 in which grease serving as a lubricant agent can be stored. The grease nipple 53 is a
30 supply port from which a lubricant agent can be supplied to the storage space S2.
[0055] Note that in the present embodiment, the storage space S1 is filled with lubricant oil, and the storage space S2 is filled with grease. Grease has a viscosity higher than that of lubricant oil.
35 [0056] As described above, the coupling surface 11C of the planting arm 11B is located at the coupling portion C, and the coupling surface 11C is a portion of the storage space S2 that is open to the outside of the planting arm 11B. A gap
14

S3 is formed between the coupling flange surface 35B and the coupling surface 11C. In other words, the coupling portion C in which the rotation case 11A and the planting arm 11B are coupled to each other is the gap S3. A ring-shaped oil seal 55 serving as a partition member is provided in the gap S3, and the oil 5 seal 55 is configured to be able to prevent the grease from leaking from the storage space S2. That is to say, the gap of the gap S3 is filled with the oil seal 55.
[0057] As shown in FIGS. 6 to 8, the coupling portion C has a spigot joint structure in which the rotation case 11A and the planting arm 11B are engaged
10 with each other, and the support shaft 35A and the coupling flange surface 35B engage with the coupling surface 11C. A portion of the support shaft 35A is surface-treated in the shape of a notch. Hereinafter, the portion that is surface-treated in the shape of a notch is referred to as “surface treated part K”. Of the gap S3, a gap of the surface treated part K is larger than gaps in other
15 portions of the gap S3, and the gaps that are in communication with each other form the “release part EW”. When a grease gun (not shown) is connected to the grease nipple 53 and grease is poured into the planting arm 11B, the internal pressure of the planting arm 11B increases. The internal pressure of the planting arm 11B is also transmitted to the oil seal 55 via the release part
20 EW. Also, when the internal pressure of the planting arm 11B increases relative to the pressing force of the oil seal 55 in the surface treated part K, the gap between the surface of the oil seal 55 and the support shaft 35A, and/or the gap between the surface of the oil seal 55 and the coupling surface 11C are enlarged. Accordingly, the storage space S2 is in communication with the
25 outside of the seedling planting mechanism 11. Also, internal air of the planting arm 11B escapes from the gap between the release part EW and the oil seal 55, and the internal air further escapes from the gap between the coupling flange surface 35B and the coupling surface 11C to the outside. Accordingly, the planting arm 11B is filled with the grease.
30 [0058] Furthermore, when the planting arm 11B is filled with grease, and the grease itself is compressed, the grease then passes through the gap between the release part EW and the oil seal 55 from which the air has escaped. Then, the grease escapes to the outside of the seedling planting mechanism 11 via the gap between the coupling flange surface 35B and the coupling surface 11C.
35 Accordingly, the release part EW is configured to allow the grease to be released from the gap S3 to the outside of the seedling planting mechanism 11 via the oil seal 55. The release part EW is formed in the surface treated part K, which is
15

surface-treated in the shape of a notch, of the rotation case 11A, of the spigot joint structure of the rotation case 11A and the planting arm 11B. Note that the oil seal 55 has a configuration in which, in a normal atmosphere pressure (for example, 80 kPa to 120 kPa), the surface of the oil seal 55 is in intimate 5 contact with the support shaft 35A and the coupling surface 11C, and in the release part EW, the storage space S2 and a portion outside of the seedling planting mechanism 11 are not in communication with each other. Therefore, the oil seal 55 is configured such that a foreign substance does not enter the storage space S2 via the oil seal 55 from the outside of the seedling planting
10 mechanism 11.
[0059] The release part EW is formed on the upper side of the central portion of the coupling portion C in the vertical direction. In the present embodiment, the release part EW is located on a side of the coupling portion C opposite to a side on which the coupling bolt Bo is located. Accordingly, when pouring
15 grease into the planting arm 11B, an operator can easily check whether or not the planting arm 11B is fully filled with the grease. In this way, the oil seal 55 serving as a partition member and the release part EW are provided on the planting arm 11B. [0060] [Other Embodiments]
20 The present invention is not limited to the configurations exemplified in
the above-described embodiment, and other representative embodiments of the present invention will be given below.
[0061] (1) In the above-described embodiment, the planting arms 11B are provided at two end portions of the rotation case 11A in the longitudinal
25 direction, but the present invention is not limited to this embodiment. The planting arm 11B may be provided at one end portion of the rotation case 11A in the longitudinal direction. In other words, the planting arm 11B may be provided in at least one end portion of the rotation case 11A in the longitudinal direction, and may be configured to be able to plant seedlings in a field.
30 [0062] (2) The above-described embodiment has described a configuration in which the release part EW is provided in the gap S3 filled with the oil seal 55, but the present invention is not limited to this embodiment. For example, as shown in FIG. 9, a configuration may also be adopted in which a ring-shaped oil-seal 56 is provided in a gap S4 formed in the central portion in the
35 longitudinal direction between the rotation case 11A, the gap portion S4 being formed between the opening oriented in the lateral direction of the machine body and the drive shaft 30. Also, a configuration is also possible in which the
16

release part EW is provided in the gap portion S4. Specifically, when a grease gun (not shown) is connected to the oil supply port 11o and lubricant oil is poured into the rotation case 11A, the internal pressure of the rotation case 11A increases. Also, when the internal pressure of the rotation case 11A increases 5 relative to the pressing force of the oil seal 56, the gap between the surface of the oil seal 56 and the opening of the rotation case 11A, and/or the gap between the surface of the oil seal 55 and the drive shaft 30 are enlarged. Accordingly, the inside of the rotation case 11A and the outside of the rotation case 11A are in communication with each other, and the release part EW is formed. That is
10 to say, the oil seal 56 serving as a partition member and the release part EW may also be provided on the rotation case 11A.
[0063] (3) In the above-described embodiment, the lubricant agent for the rotation case 11A is lubricant oil, and the lubricant agent for the planting arms 11B is grease, but the present invention is not limited to this configuration.
15 For example, the lubricant agents for the rotation cases 11A and the planting arms 11B may be grease, and the lubricant agents for the rotation cases 11A and the planting arms 11B may be lubricant oil.
[0064] (4) In the above-described embodiment, the surface treated part K is formed on the support shaft 35A, but the surface treated part K may be formed
20 on the coupling flange surface 35B. Also, the surface treated part K may be formed on the coupling surface 11C. Also, the release part EW may also be formed on the surface treated part K other than the support shaft 35A. That is to say, the release part EW may be formed in a portion of the rotation case 11A and/or a portion of the planting arm 11B that are/is surface-treated in the
25 shape of a notch, of the spigot joint structure between the rotation case 11A and the planting arm 11B.
[0065] (5) The surface treated part K is formed by metal processing, and the type of metal processing may be milling, reaming, broaching, mold engraving electric spark machining, or the like.
30 [0066] (6) A configuration is also possible in which the above-described surface treated part K is not formed.
[0067] (7) The above-described release part EW may also be formed on the lower side of the central portion of the coupling portion C in the vertical direction.
35 [0068] (8) In the above-described embodiments, the oil seals 55 and 56 are provided as partition members, but the partition members may be an O-ring, a breather, an oil seal bearing, a seal tape, or the like.
17

[0069] Note that the configurations disclosed in the above-described
embodiments (including the other embodiments) may be applied in
combinations with configurations disclosed in other embodiments, provided
there is no inconsistency.
5 The embodiments disclosed in the present specification are examples,
and the embodiments of the present invention are not limited to those embodiments and can be modified as appropriate without departing from the object of the present invention.
10 Industrial Applicability
[0070] The present invention is applicable to a field work machine that includes a plurality of seedling planting mechanisms capable of planting seedlings in a field.
15 Description of Reference Signs
[0071] 11: Seedling planting mechanism
11A: Rotation case
11B: Planting arm
11o: Oil supply port (supply port)
20 53: Grease nipple (supply port)
55: Oil seal (partition member)
56: Oil seal (partition member)
Bo: Coupling bolt
C: Coupling portion (coupling part)
25 EW: Release part
K: surface treated part (part that is surface-treated in the shape of notch)
P1: Lateral axis (lateral axis oriented in the lateral direction of machine
body)
30 S1: Storage space
S2: Storage space
S3: Gap
S4: Gap
35

WE CLAIMS

A field work machine comprising:
a plurality of seedling planting mechanisms capable of planting 5 seedlings in a field,
wherein each of the seedling planting mechanisms includes: a storage space capable of storing a lubricant; a partition member that is provided in a gap of the storage space that is open to an outside of the seedling planting mechanism, and is capable of 10 preventing the lubricant agent from leaking from the storage space; and
a release part capable of releasing the lubricant agent from the gap to the outside of the seedling planting mechanism via the partition member.
15 2. The field work machine according to claim 1, further comprising:
a supply port for allowing the lubricant to be supplied to the storage space,
wherein the partition member is configured to guide the lubricant agent to the release part when the lubricant agent is supplied from the supply port 20 and is compressed.
3. The field work machine according to claim 1 or 2,
wherein the seedling planting mechanism includes: a rotation case that
has a rotation axis at a central portion in a longitudinal direction thereof, and
25 is rotatable around the axis oriented in a lateral direction of a machine body;
and a planting arm that is provided at an end portion of the rotation case in the
longitudinal direction, and capable of planting seedlings in a field, and
the gap in a form of a coupling part in which the rotation case and the planting arm are coupled to each other. 30
4. The field work machine according to claim 3,
wherein the coupling part has a spigot joint structure in which the rotation case and the planting arm are engaged with each other, and
the release part is in a form of a surface-treated notch in either or both 35 of the rotation case and the planting arm of the spigot joint structure.
5. The field work machine according to claim 3 or 4,
19

wherein the release part is located above a central portion of the coupling part in a vertical direction.
6. The field work machine according to any one of claims 3 to 5,
5 wherein in the coupling part, the rotation case and the planting arm are
coupled to each other with a coupling bolt, and
the release part is located on a side of the coupling part opposite to a side on which the coupling bolt is located.
10 7. The field work machine according to any one of claims 3 to 6,
wherein the partition member and the release part are provided on the rotation case.
8. The field work machine according to any one of claims 3 to 7,
15 wherein the partition member and the release part are provided on the
planting arm.
9. The field work machine according to any one of claims 3 to 8,
wherein the lubricant agent for the rotation case is lubricant oil, and
20 the lubricant agent for the planting arm is grease.
10. The field work machine according to any one of claims 1 to 8,
wherein the lubricant agent is lubricant oil.
25 11. The field work machine according to any one of claims 1 to 8, wherein the lubricant agent is grease.
12. The field work machine according to any one of claims 1 to 11, wherein the partition member is an oil seal. 30