JPH10136735A - Seedling planting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a backlash absorbing mechanism able to more accurately demonstrate a function or be constituted at a low cost by devising a structure. SOLUTION: In this seedling planting mechanism for which a gear linking mechanism S for relatively linking a planting arm and a rotary case 10 so as to make a planting pawl tip part draw an almost elliptic track is equipped inside the rotary case 10, the backlash absorbing mechanism G capable of controlling the play of the planting arm by the backlash of the gear linking mechanism S is constituted of a cam 41 integrally rotated with a spindle 14 and a braking arm 42 pressurized and energized by the cam 41. The cam 41 is integrally formed by forging to a final gear 30 which is a gear on a transmission lowest side in the gear linking mechanism G integrally rotated with the spindle 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rattling absorbing mechanism capable of restricting rattling of a planting arm due to backlash. More specifically, a planting claw protrudes into a seedling on a seedling mounting table due to a backlash at a gear engaging portion. The present invention relates to a technique for preventing gear teeth in a rotary case from coming into contact with each other by impact so as to easily cause fatigue failure due to so-called "shaking" movement.

[0002]

2. Description of the Related Art The above-mentioned backlash absorbing mechanism is a cam which is disposed in the rotary case and beside the lowermost transmission gear and rotates integrally with a supporting shaft for driving a planting arm. And a swinging arm that presses and abuts.
No. 136 is known.

[0003]

SUMMARY OF THE INVENTION
Immediately before the planting claw rushes into the seedling on the seedling mounting table, the planting arm is moved forward in a direction in which the planting arm is rotationally driven by the gear interlocking mechanism in the rotary case. Is pushed back to reduce the collision shock between gear teeth due to backlash of the gear engagement portion. That is, by moving the backlash in advance, a strong shock at the time of seedling rush is eliminated.

In the conventional play absorbing mechanism, a cam having a shape in which a gradually changing portion and a sudden changing portion of a radius are combined is attached to a support shaft, so that a swing arm which is biased by a spring moves the planting arm immediately before the seedling enters. The cam is manufactured as a dedicated part separate from the gear, for example, by fitting the cam to the boss portion of the lowermost transmission side gear in the gear interlocking mechanism and welding. Therefore, there is a need for a step of integrating the gear and the cam with high accuracy so that the above-mentioned functions can be realized, and there is room for improvement because the cost of the backlash absorbing mechanism is expensive. An object of the present invention is to make it possible to configure the play-absorbing mechanism so that its function can be exhibited more accurately or at a low cost by devising the structure.

[0005]

[Means for Solving the Problems]

[Structure] In the first invention, a rotary case is rotatably supported by a planting transmission case, and a planting arm is supported at both ends of the rotary case via supporting shafts, and rotation of the rotary case is performed. A gear interlocking mechanism that links the planting arm and the rotary case relative to each other so that the tip of the planting claw provided on the planting arm draws a substantially elliptical locus along with the seedling planting inside the rotary case In the mechanism, a cam that rotates integrally with the support shaft, a backlash absorbing mechanism that can restrict rattling of the planting arm due to backlash of the gear interlocking mechanism,
The cam is formed integrally with a brake arm that is pressed and urged against the cam, is the lowermost transmission gear in the gear interlocking mechanism, and is integrally formed with a final gear that rotates integrally with the support shaft. And

A second invention is characterized in that, in the first invention, the final gear has a perfect circular shape.

According to a third aspect of the present invention, in the second aspect, the eccentric crank in which the first gear on the driving side and the second gear on the driven side driven and rotated by the first gear are unequally coupled to the gear interlocking mechanism. It is characterized by having a rotary transmission mechanism of the type.

According to a fourth aspect of the present invention, in the first to third aspects, the planting arm is assisted in the direction opposite to the rotation direction of the rotary case by the play absorbing mechanism when the planting claw is at the position for scraping the seedlings, and The shape of the cam is set so that the planting arm is assisted in the rotation direction of the rotary case when the planting claw is at the planting position of the seedling.

According to the structure of the first aspect, the cam is integrally formed with the gear on the lowermost side of the transmission in the gear interlocking mechanism, and the cam is integrally formed with the final gear that rotates integrally with the support shaft. Compared to the case where the and the cam are separately created and then integrated by welding, etc., the integration step is omitted, which is advantageous in terms of processing cost, and the occurrence of errors due to the integration process such as welding distortion And the relative positional relationship between the final gear and the cam can be easily set as set.

According to the second aspect of the present invention, since the final gear has a perfect circular shape, the final gear has a non-circular gear.
(See Japanese Patent Publication No. 108136), (a) the gear teeth are easily machined, and the state becomes more suitable for mass production. Therefore,
The integration of the perfect round final gear and cam is also a suitable part for mass production.

According to the third aspect of the present invention, the first gear on the driving side and the first gear on the driving side are provided to the gear interlocking mechanism such that the tip of the planting claw draws a substantially elliptical locus to perform the seedling collecting and planting movements. An eccentric crank type rotation transmitting mechanism (Japanese Patent Application No. 7-761) that unequally interlocks a driven second gear driven and rotated by one gear.
No. 12), all the gears can be formed in a perfect circular shape and can be easily processed, as compared with a means in which the gear interlocking mechanism draws a substantially elliptical trajectory by engaging the non-circular gears. Therefore, the cost of the gear interlocking mechanism can be reduced, and the effect (a) can be obtained.

According to the fourth aspect of the present invention, due to the shape of the cam, (1) the planting arm is assisted in the direction opposite to the rotation direction of the rotary case when the planting claw is at the position for scraping the seedlings, (2) When the planting claw is at the planting position of the seedling, the planting arm is assisted in the rotating direction of the rotary case. In the configuration of (1), as described above, the planting arm is pushed back by the load at the time of scraping the seedlings, and the conventional effect of reducing the collision shock between the gear teeth due to the backlash of the gear engaging portion is exhibited.

In the configuration (2), a braking force is applied to the support shaft, thereby having the following operation. That is, at the time of seedling planting, the pushing rod is vigorously projected and moved by the spring in order to push out the seedling held between the planting claws, so that the torque fluctuation accompanying the rotation of the rotary case greatly fluctuates (decreases). The torque fluctuation is offset by the braking force on the support shaft. Accordingly, the fluctuation of the torque of the rotary case is reduced, so that the exercise becomes smooth and the planting state of the seedlings becomes stable.

According to the present invention, the accuracy of the relative positional relationship between the final gear and the cam can be improved while the cost can be reduced as compared with the conventional one. Has been streamlined to work more smoothly.

[0015] In the seedling planting mechanism according to the second and third aspects,
There is an advantage that the backlash absorbing mechanism becomes more suitable for mass production.

According to the third aspect of the present invention, all the gears of the gear interlocking mechanism can be formed in a perfect circular shape that can be easily processed.
There is an advantage that the cost can be reduced.

In the seedling planting mechanism according to the fourth aspect, the cam for the backlash absorbing mechanism can be used for smoothing the rotation of the rotary case by devising the shape of the cam. It was even more rational that could improve the finish level.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG.
And a plurality of planting transmission cases 3 connected to the main frame 1 at appropriate intervals in the body width direction and connected to the feed case 2 connected to a substantially central portion of the body width direction.
A frame body is configured. A seedling mounting table 4 is mounted on the front of the frame so as to be reciprocated at a constant stroke in the lateral direction of the machine body, and the seedling mounting mechanism 5 can be driven on the left and right sides of the rear of each of the plurality of planting transmission cases 3. A plurality of ground floats 6 arranged side by side in the machine body direction are attached to the bottom of the frame body to constitute a seedling planting apparatus A.

The seedling planting apparatus A is configured to transmit power from the self-propelled body to the feed case 2 so that the rear part of the running body (not shown) can be moved up and down via a link mechanism (not shown). As described above to form a riding rice transplanter. Then, the ground float 6
Touches the mud surface of the field to support the weight of the machine and level the mud surface, and each seedling planting mechanism 5 cuts out a part of the mat seedling placed on the seedling mounting table 4 and the grounding float 6 It is planted at the leveling site.

As shown in FIG. 1 and FIG. 2, each of the plurality of seedling planting mechanisms 5 includes a rotary case 10 on the side of the rear part of the planting transmission case 3 around the first axis X1 in the machine body lateral direction. The seedlings are mounted so as to be driven to rotate in the rotation direction F, and are separated from the first axis X1 of the rotary case 10 and have a phase difference of 180 degrees from each other in the rotation direction of the rotary case 10. A planting arm 13 as a nail support having a nail 12 and a seedling pushing tool 15 is attached so as to rotate about a second axis X2 parallel to the first axis X1. And
Relative rotating means for relatively rotating the planting arm 13 and the rotary case 10 as the rotary case 10 is driven to rotate is provided between each planting arm 13 and the planting transmission case 3. Each of the planting arms 13 is provided with a seedling pushing operation mechanism E for operating the seedling pushing tool 15 as the is rotated.

The rotary case 10 has a two-part structure in which a half case part 10A, 10B having a dividing line Y is bolted, and the center of the right half case part 10A in the longitudinal direction is formed by the planting transmission case 3. It is rotatably attached to the rear body boss portion 3a of the fuselage through a bearing 7 via a bearing 7, and a bearing portion 10a located at a central portion in a longitudinal direction of a left half case portion 10B, and a planting transmission case 3 bears a bearing 9. The output shaft 8 is rotatably supported via a boss 3a and is connected to the end of the output shaft 8 through a tapered pin 11 so as to be integrally rotated. The power of the output shaft 8 is transmitted from the feed case 2 via a transmission chain (not shown). Thereby, the rotary case 10 is driven to rotate in the F direction around the first axis X1 with respect to the planting transmission case 3.

The planting arm 13 is connected to an end of the support shaft 14 supported by bearings 24 and 25 at the tip of the rotary case 10 and protruding outside from the rotary case 10. Flange 27 integrally formed with planting arm 13
Is attached to the support shaft 14 such that the end of the support shaft 14 enters the through hole 29 of the flange portion 27, and the plant is tightened and connected to the flange portion 26 fixed to the support shaft 14 by a bolt 28. The attached arm 13 and the support shaft 14 can be rotated integrally. As a result, the planting arm 13 is moved to the second position of the support shaft 14 parallel to the first axis X1.
It is rotatably supported by the rotary case 10 around the axis X2.

As shown in FIGS. 2 and 3, each of the pair of relative rotation means includes a sun gear 23 externally rotatably fitted to the output shaft 8 and a first axis X1 and a second axis X2. A first intermediate gear having a third axis X3 between them (an example of a first gear)
31, a second intermediate gear (an example of a second gear) 32 having a fourth axis X4, a passive gear (corresponding to a final gear) 30 that rotates integrally with the support shaft 14, and a first intermediate gear 31 and a second intermediate An eccentric crank type interlocking mechanism (corresponding to a rotation transmission mechanism) D extending over the gear 32 is configured.

By engaging the meshing claw B formed on the boss of the sun gear 23 with the meshing claw formed on the end of the boss 3a of the planting transmission case 3, the planting transmission case is formed. Numeral 3 fixes the sun gear 23 so that it cannot rotate. Since the first intermediate gear 31 and the sun gear 23 are in mesh with each other, and the second intermediate gear 32 and the passive gear 30 are in mesh with each other, the sun gear 23 and the planting arm 13 are mutually connected via the interlocking mechanism D. An interlocking transmission mechanism S for interlocking rotation in the direction is configured.

The interlocking mechanism D includes a crank-shaped gear support shaft 5 including a first round shaft portion 51, a second round shaft portion 52, and a connecting shaft portion 53.
0, and the first and second intermediate gears 31 and 32. That is, as shown in FIG. 7, the connecting shaft portions 53a, 53a of the connecting shaft portion 53 are connected to the first shaft center 53 having the third shaft center X3.
The first mounting holes 51c of the round shaft portion 51 and the mounting holes 52c of the second round shaft portion 52 having the fourth axis X4 are fitted into the mounting holes 51c, respectively. The round shaft portion 51 and the second round shaft portion 52 are supported in a two-sided state while having a displaced axis. In addition, 53c
Are positioning projections fitted to the rotary case 10;
Is a relief hole.

A pair of ridges 3 is provided on the side of the first intermediate gear 31.
9 and 39 are formed, and the crank pin 36 is press-fitted and integrated with the second intermediate gear 32. The crank pin 36 is
The projection 39 on the third axis X3 side pushes the crank pin 36 on the fourth axis X4 side so as to fit into the groove 38 formed between the pair of projections 39, 39. The interlocking mechanism D functions so that the first intermediate gear 31 rotates the second intermediate gear 32 unequally.

That is, when the rotary case 10 is driven to rotate and the sun gear 23 is fixed, the first intermediate gear 31 rotates around the third axis X 3 and its rotational force is transmitted by the crank pin 36. Then, the second intermediate gear 32 rotates around the fourth axis X4. The eccentricity between the third axis X3 and the fourth axis X4 causes the crank pin 36 to reciprocally slide in the radial direction of the first intermediate gear 31 in the groove 38 formed by the pair of ridges 39, 39 while rotating. To communicate. Therefore, even if the first intermediate gear 31 rotates at a constant speed, the interlocking mechanism D rotates the second intermediate gear 32 at an unequal speed.
The first and second intermediate gears 32 function so as to rotate in conjunction with each other in a phase relationship M1 shown in FIG.

The sun gear 23, the first and second intermediate gears 31,
The positional relationship between the rotary gear 10, the passive gear 30, and the rotary case 10 is set such that the rotary case 10 and the passive gear 30 rotate relative to each other in a phase relationship N1 shown in FIG. . Thereby, the relative rotation means drives the pair of planting arms 13 and 13 and the rotary case 10 to relatively rotate with the phase relationship N1 in FIG. 9 as the rotary case 10 is driven to rotate. Then, the pair of planting arms 13 and 13 are caused to perform a planting movement in which the tip of each planting claw 12 draws a substantially elliptical locus T1 shown in FIG.
When the phase of the passive gear 30 changes in the negative direction, the planting arm 13 rotates in the ground rising direction u shown in FIG. 9, and when the phase of the passive gear 30 changes in the + direction, the planting arm 13 rotates. The attached arm 13 rotates in the ground descent direction d shown in FIG.

As shown in FIG. 4, the seedling pusher 15 is fixed to one end of a support rod 15a that supports the planting arm 13 to slide along the planting claw 12, so that the planting pusher 15 can be planted. The attachment arm 13 is supported so as to move along the planting claw 12. As shown in FIGS. 2 and 4, the seedling pushing operation mechanism E protrudes outside from the planting arm 13 of the camshaft 16, the balance arm 20, the pushing spring 22, and the camshaft 16 provided inside the planting arm 13. It is constituted by a connecting member 18 and the like connected to the end portion.

The cam shaft 16 is rotatably supported by the planting arm 13 about the same axis as the second axis X2, and is integrally provided with a cam 17 for operating the seedling pushing tool 15. ing. The balance arm 20 includes the planting arm 13.
Is rotatably supported by the support shaft 20a. One end of the balance arm 20 is connected to the support rod 15a by a link 19.
And the other end of the balance arm 20 has a cam 17
Is provided. The push-out spring 22 slidably urges the balance arm 20 by using the planting arm 13 as a reaction force member to slidably urge the support rod 15 a to the side protruding from the planting arm 13, and to push the balance arm 20. The cam follower 21 is pressed against the peripheral surface of the cam 17 to be urged.

The connecting member 18 is attached across the cam shaft 16 of one of the planting arms 13 and the cam shaft 16 of the other planting arm 13.
0, the camshaft 16 rotates with the rotary case 1.
The cam shaft 16 is supported so as not to rotate with respect to zero. Accordingly, as the seedling-planting claw 12 performs the seedling-planting motion, the planting arm 13 and the cam shaft 16 rotate relatively, and the balance arm 20 presses the cam 17 against the cam follower 21 and pushes the spring out. The support rod 15a is slid around the support shaft 20a by the swing operation for the operation of the support rod 15a.

Accordingly, the seedling pushing operation mechanism E moves the rotary case 10 as the seedling-attached claw 12 performs seedling-planting movement.
And pushes the seedling pushing tool 15 to the operating position located on the tip side of the seedling mounting claw 12 as shown by the two-dot chain line in FIG. 4, the retraction operation is performed by the operation force of the cam 17 to a non-operation position located on the base end side of the seedling claw 12 with respect to the operation position as shown by a solid line in FIG.

Therefore, when the rotary case 10 is driven to rotate, the seedling-arms 13, 13 are rotated.
Of the seedling, the tip of the seedling claw 12 draws a substantially elliptical locus T1 while the orbit rotates around the first axis X1 and rotates about the second axis X2 by the action of the relative rotation means. The seedling placement claw 12 is caused to perform a seedling movement so as to rotate up and down between the seedling outlet of the mounting table 4 and the field, and the seedling pushing operation mechanism E provided in each seedling arm 13 is rotated by a rotary. The seedling pushing tool 15 is driven by the rotational force of the case 10 to move the seedling pushing tool 15 between the non-acting position and the acting position in conjunction with the seedling movement of the seedling-claw 12.

Thus, the seedling placement claw 12 of the one seedling placement arm 13 and the seedling placement claw 12 of the other seedling placement arm 13 are formed.
Alternately, block seedlings for one plant are cut and taken out from the mat-shaped seedlings placed on the seedling mounting table 4, and are transported down to the field to be planted on the same planting strip.
Then, while each seedling-attached claw 12 is moved downward from above the seedling outlet of the seedling mounting table 4 to the seedling-planting position, the seedling pushing tool 15 is in the non-operating position, and the seedling-claw 12 is removed. When the planted seedlings 12 reach the field and plant seedlings, the seedling pushing tool 15 is in the operating position, and the seedlings held by the planted seedlings 12 are transferred to the seedlings. The pushing operation is performed so as to easily separate from the planting claws 12.

The crank pin 36 is formed as a non-circular pin having a notch C on the outer periphery as shown in FIGS. The notch portion C is a portion of the outer peripheral portion of the crank pin 36 facing the rotation axis X4 of the second intermediate gear 32, and does not contact the inner wall surfaces 38a of the pair of groove portions 38, so that the two The second intermediate gear 32 is formed in an arc shape having a radius R1 and centered on the rotation axis X4 of the second intermediate gear 32, while being disposed at a position not involved in the interlocking of the gears 31 and 32. Radius R
1 is larger than the radius R2 of the shaft hole 32a of the second intermediate gear 32, so that the peripheral surface 36a at the notch C of the crankpin 36 is formed into an arcuate surface, and the peripheral surface 3a
A radius R1 as an interval between 6a and the rotation axis X4 is formed to be larger than a radius R2 of the shaft hole 32a. As a result, the spacer portion 53b of the gear support shaft 50 enters the cutout portion C, and a gap exists between the spacer portion 53b and the peripheral surface 36a, and the crank pin 36 contacts the spacer portion 53b of the gear support shaft 50. The two intermediate gears 31, 32 are interlocked while revolving without rotating.

Next, the backlash absorbing mechanism G in the interlocking transmission mechanism S will be described. As shown in FIGS. 2 and 10, a rattle absorbing mechanism G capable of restricting rattling of the planting arm 13 due to backlash of the interlocking transmission mechanism S is wound around a cam 41 integrally rotating with the support shaft 14 and the cam 41. A brake arm 42 pressed and urged by a spring 43,
A cam 41 is integrally formed with a passive gear (equivalent to a final gear) 30 which is a lower gear of the transmission in the interlocking transmission mechanism S and rotates integrally with the support shaft 14 by forging. Maximum diameter portion of cam 41 (large diameter peripheral surface 41c described later)
Is made smaller than the root circle diameter of the gear portion 30g of the passive gear 30 so that the tooth shape of the gear portion 30g can be formed integrally or cut later to facilitate machining. is there. The braking arm 42 is swingable about a fulcrum Z in the left-right direction, and the leading end side thereof is constantly pressed against the peripheral surface of the cam 41 by a winding spring 43 so as to be in sliding contact therewith.

The shape of the cam 41 is as follows.
When the seedling is at the scraping position at the lower end (the position indicated by a in FIG. 1), the planting arm 13 is assisted in the direction opposite to the rotation direction of the rotary case 10, and the planting claws 12 are planted. When in the position (position indicated by b in FIG. 1), the setting arm 13 is set so as to be assisted in the rotation direction of the rotary case 10. That is, in FIG. 10, the rotary case 10 is in the direction of arrow A around the axis X1 (the direction of arrow F in FIGS. 1 and 2), and the planting arm 13 is in the direction of arrow X.
The cam 41 rotates around the rotary case 10 in the direction of the arrow B. The cam 41 has an acceleration projection 41a corresponding to the position where the seedlings are scraped and a braking projection 41b corresponding to the position where the seedlings are planted. I have.

That is, when the planting claw 12 is located before the scraping position, the braking arm 42 is connected to the large-diameter peripheral surface 4 of the cam 41.
1c, and when the planting claw 12 comes immediately before the scraping position, the cam diameter suddenly decreases, so that the braking arm 42 comes into sliding contact with only the acceleration projection 41a. For a short time until the cam 41 contacts the small-diameter peripheral surface 41d, as shown in FIG. 12, the backlash absorbing mechanism G assists the cam 41 in the rotation direction (the direction of arrow B).
Works. That is, by urging the planting arm 13 to move in advance, the backlash of the gear in the interlocking transmission mechanism D causes the planting claw 12 to be pushed back by the load resistance when the planting claw enters the seedling, and the gear teeth are moved. It is possible to eliminate the possibility of repeated fatigue destruction due to repeated impact occlusion.

When the planting claw 12 is located just before the planting position, the braking arm 42 is connected to the small diameter peripheral surface 41 of the cam 41.
d, and when the planting claw 12 comes to the planting position, the cam diameter suddenly increases, so that the braking arm 42 comes into sliding contact with only the braking protrusion 41b, and the braking arm 42 becomes large. For a short period of time until the contact with the radial peripheral surface 41c, as shown in FIG. 13, the cam 41 is assisted in a direction opposite to the rotation direction (the direction of arrow B), that is,
The backlash absorbing mechanism G functions to brake the cam 41.

By setting the lever ratio based on the positional relationship between the fulcrum Z of the braking arm 42 and the axis X2 of the cam 41, the pressing point of the acceleration projection 41a of the braking arm 42 is relatively close to the fulcrum Z and moves away from the acceleration projection 41a. To the braking projection 41b of the braking arm 42, which is relatively far from the fulcrum Z, and relatively softly presses the approachingly moving braking projection 41b so that an appropriate braking action is generated. is there. Thus, in the seedling placement position, the sudden reduction of the rotational drive load due to the release of the compression action of the push-out spring 22 of the support rod 15a is performed by applying a braking force to the cam 41, that is, to the support shaft 14. By offsetting each other, the seedling planting mechanism 5 can be smoothly driven with the torque fluctuation as small as possible, and there is an operational effect that the seedling planting posture can be further stabilized.

By the way, the fine adjustment mechanism H of the relative position of the planting arm 13 with respect to the rotary case 10 around the axis X2.
Is a nut portion 1 of the planting arm 13 as shown in FIG.
3n, an adjusting bolt 44 screwed to the
4, two flanged nuts 45, 45 screwed into
And a holding portion 26a of the flange portion 26.
That is, the two flanged nuts 45, 45 are locked to the adjustment bolt 44 in a back-to-back state in which the flanges thereof are separated from each other, and the holding portion 26a holds the flanges of the two flanged nuts 45 in a state of being held therebetween. It is fitted. Therefore, the relative position between the flange 26 and the planting arm 13 is finely adjusted by loosening the bolt 28 and then turning the adjustment bolt 44, and then the bolt 28 is tightened to complete the fine adjustment operation.

[Another Embodiment] The gear support shaft 53 in the rotation transmission mechanism D may be one in which the first round shaft portion 51, the second round shaft portion 52, and the connecting shaft portion 53 are integrally formed. Further, the final gear 30 may be one in which the cam 41 is integrally formed by casting or sintering.

[Brief description of the drawings]

FIG. 1 is a side view of the entire seedling planting apparatus.

FIG. 2 is a sectional view of a seedling planting mechanism.

FIG. 3 is a sectional view of a rotary case.

FIG. 4 is a sectional view of a planting arm.

FIG. 5 is a perspective view of the rotation transmitting mechanism in an exploded state.

FIG. 6 is a front view of a second intermediate gear.

FIG. 7 is a perspective view of the gear support shaft in an exploded state.

FIG. 8 is an explanatory diagram of an interlocking relationship between a first intermediate gear and a second intermediate gear.

FIG. 9 is an explanatory diagram of an interlocking relationship between a rotary case and a passive gear.

FIG. 10 is a cross-sectional view of a main part showing a structure of a play absorbing mechanism.

FIG. 11 is a side view showing the structure of a fine adjustment mechanism.

FIG. 12 is a state diagram showing an assisting (accelerating) action when scraping a seedling.

FIG. 13 is a state diagram showing an assisting (braking) effect at the time of planting seedlings.

[Explanation of symbols]

 REFERENCE SIGNS LIST 3 Planting transmission case 10 Rotary case 12 Planting claw 13 Planting arm 14 Support shaft 30 Final gear 31 First gear 32 Second gear 41 Cam 42 Braking arm D Rotation transmission mechanism G Gap absorption mechanism S Gear interlocking mechanism

Claims (4)

[Claims] 1. A rotary case is rotatably supported by a planting transmission case so as to be rotatable, and a planting arm is supported at both ends of the rotary case via supporting shafts, and the rotary case is rotated with the rotation of the rotary case. A seedling having a gear interlocking mechanism for relatively interlocking the planting arm and the rotary case so that the tip of the planting claw provided on the planting arm follows a substantially elliptical locus. A cam that rotates integrally with the support shaft, and a braking arm that is pressed and urged by the cam, the backlash absorbing mechanism being capable of controlling rattling of the planting arm due to backlash of the gear interlocking mechanism. A seedling planting mechanism, wherein the cam is formed integrally with a final gear that is the lowermost transmission of the gear interlocking mechanism and that rotates integrally with the support shaft. 2. The seedling-planting mechanism according to claim 1, wherein the final gear has a perfect circular shape. 3. An eccentric crank type rotation transmitting mechanism for unequally interlocking a driving-side first gear and a driven-side second gear driven and rotated by the first gear in the gear interlocking mechanism. 3. The seedling planting mechanism according to claim 2, wherein 4. The planting arm is assisted by the backlash absorbing mechanism in a direction opposite to a rotation direction of the rotary case when the planting claw is at a position where the seedling is scraped, and the planting claw is moved by the seedling. When in the planting position, so that the planting arm is assisted in the rotation direction of the rotary case,
The seedling planting mechanism according to any one of claims 1 to 3, wherein a shape of the cam is set.