JPH088811B2 - Planting claw drive mechanism of rice transplanter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] According to the present invention, planting claws are attached to both ends of one rotationally driven planting case so that planting can be performed twice by one rotation. The present invention relates to a planting claw drive mechanism of a rice transplanter configured.

[Conventional technology]

Examples of the planting claw drive mechanism include, for example, Japanese Patent Laid-Open No. 60-221.
The ones disclosed in JP-A-009 and JP-A-63-74413 are known.

The former (Japanese Patent Laid-Open No. 60-221009) is such that a planting case is connected and fixed to a drive shaft that laterally protrudes from the planting mission case and is rotationally driven, and a sun gear is mounted at the center of rotation in the planting case. The plant gear is arranged in a fixed state with respect to the planting mission case, a pair of planting claws are provided at both ends of the planting case, and a final gear is fixed to a support shaft that supports the planting claws. A pair of intermediate gears that rotate integrally with each other and one of the final gears are arranged, and the sun gear and one of the intermediate gears are made into true circle gears to engage with each other, and the other intermediate gear and the final gear are eccentric. By engaging the gears (or elliptical gears) with each other to form a gear train that rotates the support shaft that supports the planting claw once at a non-constant speed in the opposite direction with one rotation of the planting case at a constant speed, Therefore, each rotation during rotation of the planted case To determine the attitude of both the planting claw in the phase, each planting claw is configured to Yuku is planted in the field cut out seedlings to alternately than seedling platform.

In the latter (Japanese Patent Laid-Open No. 63-74413), the planting case is connected and fixed to a drive shaft that laterally protrudes from the planting mission case and is rotationally driven. A non-circular sun gear is arranged in a fixed state with respect to the planting mission case, and a pair of planting claws are provided at both ends of the planting case. A support for fixing a gear and further disposing a non-circular intermediate gear that meshes with the sun gear and one of the final gears to support the planting claw with one rotation of the planting case at a constant speed. Configure the gear train to rotate the shaft one time in the opposite direction at a non-constant speed, and determine the posture of both planting claws in each rotation phase during the rotation of the planting case, so that each planting claw moves from the seedling stand. The seedlings are alternately cut out and planted in the field.

[Problems to be Solved by the Invention]

The former uses a sun gear, a pair of intermediate gears, and a gear train consisting of a final gear as a gear train that includes the engagement of a set of eccentric gears (or elliptical gears), and The claw posture is gradually corrected to set the tip end locus of the planting claw into a vertically long loop shape extending from the lower end of the seedling stand to the field scene. Compared with the loop of the nail tip locus in the planting drive mechanism of, the front and rear width is considerably wider, and when planting with the nail tip locus loop with such a large front and rear width, it is large in the planting site in the field scene. Claw marks remained, and the planted seedlings were prone to fall and rise.

Considering the problems of the above-mentioned conventional means, since a circular eccentric gear or an elliptical gear is used as a different-diameter gear included in the gear train for causing the planting claw to rotate at a non-uniform speed, The only change factor is the amount of eccentricity for eccentric gears and the ratio of the major axis to the minor axis for elliptical gears. The degree of freedom is low, and this is the cause of the appearance of a claw tip locus loop with a large front-back width.

On the other hand, in the latter, the sun gear, the final gear, and the gear train consisting of the intermediate gear that meshes with both gears are made into a non-circular gear train to gradually correct the pawl posture during the planting pawl moving process, and The trail of the attached nail is set in the form of a vertically long loop extending from the lower end of the seedling stand to the field scene, and the degree of freedom for setting the characteristics of the non-constant rotation of the attached nail is higher than that of the former means. It is possible to reveal a claw tip locus loop with a smaller front-back width.

However, in this latter case, the sun gear, the final gear, and the intermediate gear are engaged in series to realize one reverse rotation of the planting claw with respect to one rotation of the planting case. , All gears are gears with the same number of teeth and the same pitch curve, and when the characteristics of one set of gear meshes are determined, the characteristics at other gear meshing points are naturally determined. The degree of freedom in setting the characteristics of the high speed rotation is not always sufficient.

Further, when a non-circular gear is introduced into such a planting pawl drive mechanism, it is expected that the following strength problem will occur. In other words, if a non-circular gear that satisfies the inconstant velocity motion to obtain the required loop of the claw tip locus is created with a normal involute tooth profile, the occurrence of undercut is avoided in the phase part where the radius of curvature of the pitch curve is small. I will not be able to.

Therefore, foreign matter such as pebbles is caught in the outlet of the seedling stand and the safety clutch interposed in the planting claw drive system is activated, causing a tooth breakage accident when excessive torque is suddenly applied to the gear train. There was a fear.

The present invention has been made on the basis of such an actual situation, and has a highly durable gear train capable of making a nail tip locus in a planting case rotating type planting claw drive mechanism into a desired longitudinal length. It is intended to be provided as a thing.

[Means for solving the problem]

In order to achieve the above object, the present invention has the following configurations. That is, the planting case is connected and fixed to the drive shaft that laterally protrudes from the planting mission case and is rotationally driven, and the sun gear is fixed to the planting mission case at the center of rotation in the planting case. And a pair of planting claws are provided at both ends of the planting case, a final gear is fixed to a support shaft that supports the planting claws, and the sun gear and the final gear are integrally rotated. A pair of intermediate gears are arranged, and the sun gear, the pair of intermediate gears, and the final gear constitute a two-stage gear train that includes gears of different diameters, and both plants are in each rotation phase during rotation of the planting case. Determine the posture of the nail attachment, each planting nail is a planting nail drive mechanism of the rice transplanter configured to alternately cut out the seedlings from the seedling stand and plant them in the field, the sun gear, a pair of Non-circular for intermediate gear and final gear In addition to the gear, the tooth bottom of each gear is formed into a tooth profile formed by a curve in which the curvature changes continuously, and the tip of the planting claws is inserted into the take-out port of the seedling stand in a rotational phase. The tool pressure angle of the tooth profile and the height of the addendum were set so that the occlusal line of action at the occlusal part of each gear could approach or pass through the curved part of the tooth bottom.

[Action]

According to the above configuration, the non-uniform velocity characteristics due to the meshing of the sun gear and one intermediate gear, and the non-uniform velocity characteristics due to the meshing of the other intermediate gear and the final gear can be set independently of each other, and The number of interlocking teeth between the sun gear and one intermediate gear does not have to be the same as the number of interlocking teeth between the other intermediate gear and the final gear.

In addition, when the planting claw is locked at the take-out port of the seedling placing table by pinching foreign matter such as pebbles, a safety clutch interposed in the planting claw drive system works, but this operation is performed instantly. A large torque is shocked to act on the gear train for driving the attached pawl.

In this case, one tooth bending moment is received by the load acting on the occlusal part of the gear, but this occlusal load works along the occlusal action line and is very close to the curved part of the tooth bottom or the curved part. Pass through. Therefore, the bending stress is dispersed at the curved base of the tooth as a cantilever.

〔The invention's effect〕

As is clear from the above description, according to the present invention,
Since the pitch curve of the non-circular gear can be set individually in the meshing of the gear trains of each stage, the degree of freedom for setting the transmission characteristics of the entire gear train can be increased, and as a result, the non-circular gear set to the free pitch curve can be set. It is possible to obtain a desired speed change characteristic by configuring a gear train using, and to obtain a vertically long nail tip locus loop with a small front and rear width. Therefore, seedling removal in a suitable nail posture and a suitable nail posture It was possible to construct a planting claw drive mechanism that enables planting in.

Also, when the tip of the nail rushes into the seedling take-out opening and locks,
Thus, it was possible to provide a planting pawl drive mechanism that can be operated favorably for a long period of time without being damaged by teeth even when subjected to an impact overload.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings regarding a seedling planting device for a riding type rice transplanter.

As shown in FIG. 6, the planting case (2) is rotatably supported around the horizontal axis (P) at the rear end of the planting mission case (1), and both ends of the planting case (2) are supported. To 2
Equipped with a pair of planting claws (3), planting case (2)
2 sets of planting claws (3) are alternately cut out from the seedling take-out stand (4) at the lower end of the seedling stand (4) and planted in the field. A float (5) for leveling and maintaining posture is provided under the planted mission case (1).
Is provided, and these seedling planting devices are parallel four-wheel links (6).
It is connected to the rear part of the passenger traveling body (not shown) via the so as to be able to move up and down.

Next, the structure inside the planting case (2) will be described in detail. As shown in FIG. 1, the drive shaft (7) is arranged along the horizontal axis (P) from the planting mission case (1) to the left and right. The planting case (2) is projected and fixed to both ends of the drive shaft (7), and is also attached to a passive sprocket (8) provided at the center of the drive shaft (7) via a chain (9). Power is being transmitted. And the drive shaft (7)
Has a cylindrical shaft (10) fixed to the planted mission case (1) and fitted into the planted case (2).
The sun gear (1) is attached to the cylindrical shaft (10) in the planted case (2).
1) is fixed.

Next, the planting claw (3) and its mounting structure will be described. As shown in FIGS. 1 and 5, the planting case (2) is shown.
A fixed shaft (12) is projected laterally from both ends, and a cylindrical support shaft (13) is loosely fitted onto the fixed shaft (12).
The planting claw support case (14) is fixed to the support shaft (13). The planting claw (3) is bolted and fixed to the tip of the planting claw support case (14), and a seedling pushing-out tool (15) which can freely move back and forth along the planting claw (3) is provided. And the seedling extruding tool (15) has its support rod (15
a) The spring (16) acting on the rear end is biased in the protruding direction. A swing arm (18) pivotally supported by a fulcrum shaft (17) is engaged with the rear end of the seedling pushing tool support rod (15a), and a cam follower continuously provided from this swing arm (18). The part (18a) is in contact with the outer periphery of the cam (19) integrally formed with the fixed shaft (12). Then, while the planting claw (3) cuts out the seedling from the seedling take-out port (4a) and brings it into the field scene, as shown in the figure, the cam follower portion (18a) of the swing arm (18) has a large cam (18). By acting on the diameter part, the seedling pushing tool (15) is retracted against the spring (16),
When the planting claw (3) plunges into the field, the swing arm (1
When the cam follower part (18a) of 8) is disengaged from the large diameter part of the cam (19), the seedling pushing tool (15) is rapidly projected by the spring (16), and the tip of the planting claw (3) and the seedling pushing tool. (15) The seedlings held by and are extruded, separated and planted in the field.

Next, the structure that determines the posture of the planting pawl (3) will be described in detail. The final gear (20) is fixed to the support shaft (12) of the planting pawl support case (14) and the final gear (20 ) And the sun gear (11), an intermediate shaft (21) is arranged and supported. The first intermediate gear (22) that meshes with the sun gear (11) and the second intermediate gear (23) that meshes with the final gear (20) are integrally fixed to the intermediate shaft (2). ing. Then, the sun gear (11) and the intermediate gear (2
2), (23), and the final gear (20) have the same number of teeth,
It is composed of non-circular gears of the same module and is manufactured by sintering.

The gear train composed of the gear group described above rotates the planting claw support case (14) one revolution in the opposite direction at a non-constant speed with respect to one rotation (revolution) of the planting claw (2). 3)
The tip locus (S) of the planting claw support case (14) is set in a vertically long loop shape in order to obtain the planting claw tip locus (S) shown in the figure. It is necessary to rotate at a non-constant speed, and therefore the gear group is configured as a non-circular gear.

In this case, the degree of non-circularity of each gear (11), (22), (23), (20) is (maximum pitch curve radius Rmax) / (minimum pitch curve radius
Rmin) = 1.3 to 1.5.

In addition, the specifications of the gear train and gears are as follows: The distance between the sun gear (11) and the first intermediate gear (22) is approx.
40mm Distance between second intermediate gear (23) and final gear (20) = approx.
40mm Module m = 2.0 Tool pressure angle α = 25 ° Addendum length = 1.2m (module) or less, and the bottom of the tooth is formed into a curve with continuously changing curvature Has a proper radius.

FIG. 3 shows the meshing state of the gear train in the rotational phase in which the tip of the planting claw (3) is projected into the take-out port (4a) of the seedling stand (4). In this state, foreign matter such as pebbles is caught in the outlet (4a) and the planting pawl (3) is locked, and the safety clutch (not shown) interposed in the planting pawl transmission system slips. In other words, the maximum load is applied to the gear train. As is clear from the figure, since the tooth profile of each gear (11), (22), (23), (20) is set as described above, the occlusal action line at the occlusal part is It will approach the continuous curved portion formed at the bottom or pass through the curved portion.

In this way, the occlusal action line A, that is, the load action line passes near the curved portion of the tooth bottom, so that even if an excessive load is applied, the stress is dispersed at the base of the tooth and the durability is high. Is there.

In addition, in order to further increase the strength of the tooth profile, the pressure angle of the tool
It is recommended to set it between 25 ° and 28 °.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view of a planting pawl drive mechanism according to the present invention, FIG. 2 is a side view showing the whole and a part of a gear train, and FIG. 3 is a gear at the time of plunging a planting pawl into an outlet. FIG. 4 is a side view showing a part of a row, FIG. 4 is a side view of a planting mechanism, FIG. 5 is a vertical side view of a planting claw support case portion, and FIG. 6 is a side view showing a seedling planting device portion of a rice transplanter. It is a figure. (1) …… Planting mission case, (2) …… Planting case, (3) …… Planting nail, (4) …… Seedling support, (7)…
… Drive shaft, (11) …… Sun gear, (13) …… Support shaft,
(20) …… Final gear, (22), (23) …… Intermediate gear.

Claims (1)

[Claims] 1. A planting case (2) attached to a drive shaft (7) which is laterally projected from the planting mission case (1) and is driven to rotate.
And fixing the sun gear (11) to the planting case (2) at the center of rotation in the planting case (2) in a fixed state with respect to the planting case (2). A pair of planting claws (3) are provided at both ends, and a final gear (20) is fixed to a support shaft (13) that supports the planting claws (3), and further the sun gear (11) and the final gear (20). ) And a pair of intermediate gears (22) and (23) that rotate integrally with each other, and the sun gear (11) and the pair of intermediate gears (2).
2), (23) and the final gear (20) constitute a two-stage gear train including gears of different diameters, and the two planting claws (3) at each rotation phase during rotation of the planting case (2). A planting claw drive mechanism of a rice transplanter configured to determine postures and alternately plant each planting claw (3) from a seedling stand (4) to plant in a field. (11), the pair of intermediate gears (22), (23) and the final gear (20) are each configured as a non-circular gear, and the bottom of each gear is formed by a curve whose curvature continuously changes. The gears (11), (12), (2) are configured in a tooth shape, and in the rotational phase in which the tip of the planting claw (3) protrudes into the outlet (4a) of the seedling stand (4).
3) and (20) are characterized in that the tool pressure angle of the tooth profile and the height of the addendum are set so that the occlusal action line at the occlusal part approaches the curved part of the tooth bottom or passes through the curved part. A planting claw drive mechanism for a rice transplanter.