JPH088810B2 - 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, a two-stage gear train that rotates the support shaft that supports the planting claw once in the opposite direction at a non-constant speed with one rotation of the planting case at a constant speed is formed. Configured, so that the planting case is rotating To determine the orientation of both planting claw in rotational phase, each planting claw is configured to Yuku by planting in the field cut seedlings alternately from 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 sequentially engaged in series to form one of the planted cases.
Since one reverse unequal speed rotation of the planting claw is realized with respect to rotation, all gears are gears with the same number of teeth and the same pitch curve, and the characteristics of a set of gear engagements are determined. Therefore, the characteristics at other gear meshing points are naturally determined, and the degree of freedom for setting the characteristics of the non-constant speed rotation of the planting claw is not always sufficient.

Therefore, the present inventor first determined a loop of the path of the tip of the nail, and attempted a means for causing the planting nail to rotate at a non-constant speed so as to satisfy the loop. In this case, the shift characteristics required for the gear train cannot be satisfied by the circular eccentric gear or the elliptical gear. Therefore, the rotation angles of the input and output shafts of the gear are θ,
When φ, the angular velocity ratio curve (dφ / d
A non-circular gear having a free-form pitch curve obtained by designating θ) = f (θ) is required.

However, there is a problem here in manufacturing such a non-circular gear.

In other words, if a non-circular gear that satisfies the non-uniform velocity motion required to obtain the loop of the claw tip locus required by the planted claw drive mechanism of this mechanism is created with a normal involute tooth profile, the radius of curvature of the pitch curve is small. Occurrence of undercut is unavoidable in the part. For example, the value of the minimum radius of curvature of the pitch curve of the gear used in this example is about 10.2 mm, which is 10 teeth in the tooth profile of the same module as the example when converted into an equivalent circular gear, and the undercut Will inevitably occur. Of course, if the tooth profile module is made smaller, the problem of undercut can be suppressed and smooth occlusion can be obtained, but by making the module smaller, the gear width is increased by the amount of the decreased strength, especially at the seedling take-out port. As a planting drive mechanism that requires miniaturization as much as possible, it must be sufficiently durable even when excessive torque is applied, such as when a safety clutch in the planting pawl drive mechanism is caught by foreign matter. Has a limit.

In addition, it is expensive to manufacture a non-circular gear with an ordinary gear cutting device, and there are restrictions on the cost.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems when a toe locus is made vertically long in a planting case rotating type planting claw driving mechanism.

[Means for solving the problem]

To achieve the above object, the present invention is characterized in that a planting case is connected and fixed to a drive shaft that laterally protrudes from a planting mission case and is rotationally driven, and a solar system is installed at a center of rotation in the planting case. The gears are 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 the final gear is fixed to a support shaft that supports the planting claws. A pair of intermediate gears that rotate integrally is arranged between the sun gear and the final gear, and the sun gear, the pair of intermediate gears, and the final gear constitute a two-stage gear train including gears of different diameters, The planting claws of the rice transplanter configured to determine the postures of both planting nails in each rotation phase during rotation of the planting case and alternately cut out the seedlings from the seedling stand and plant them in the field. A drive mechanism, wherein the sun gear The intermediate gear and an identical number of teeth of the final gear is molding, with composing the non-circular gear of the same module, the specifications, (maximum pitch curve radius Rmax) / (minimum pitch curve radius
Rmin) = 1.3 to 1.5 (for each gear) Module m = (0.025 to 0.075) × axis distance Tool pressure angle α = 20 ° to 28 ° Addendum length = 1.2m (module) or less The point is that the bottom is formed into a tooth profile formed by a curve whose curvature continuously changes.

[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.

Also, a large stress concentrates on the root portion where the radius of curvature of the pitch curve becomes small, but by avoiding this, it is necessary to set the pitch curve of each gear to a relatively free shape without reducing the strength of the gear. Therefore, it is possible to set the characteristic of non-uniform rotation of the planting claw with respect to the rotation of the planting case with a large degree of freedom.

〔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.

In particular, by setting the specifications of each non-circular gear as described above, it is possible to avoid a decrease in strength due to undercut, etc. while making the module relatively large, and to reduce the size of the gear without increasing the width of the gear. The mechanism can now exert the desired function.

Further, by using such a non-circular gear as a molded gear, machining of a desired tooth profile becomes easier as compared with cutting, and cost reduction can be achieved.

〔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. 7, 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 6, 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 for determining the posture of the planting pawl (3) will be described in detail. The final gear (20) is fixed to the support shaft (13) 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 with the characteristics shown in FIG.
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 ° Tip length = 1.2m (module) or less, and the bottom of the tooth is formed by a curve with continuously changing curvature In addition, the broken line in FIG. 3 shows the case where the standard involute tooth profile is assigned to the non-circular pitch curve, and there is a difficulty in strength.

The above-mentioned gear specifications are examples, but the module m is
From the viewpoint of occlusal strength, module m = (0.025 to 0.075) x distance between axes Also, in order to secure the strength of the tooth profile, the tool pressure angle α = 20 ° to 28 ° is suitable.

When designing the specific tooth profile of each gear (11), (22), (23), (20), the angular velocity ratio curve dφ / dθ = f (θ) is set so that the desired non-uniform speed rotation is performed. Determine the pitch curve of each gear obtained from the computer by assigning the desired module to it, tooth allocation,
Further, the tooth profile of each gear is finally corrected by the means proposed here to reduce the strength due to undercut, etc., and finally the tooth profile of each gear is determined, and the die for sintering molding is manufactured based on this. is there. In addition to sintering and forming, fine blanking or the like can be considered as a forming means.

[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 side view showing a part of a tooth profile of a non-circular gear. 4 is a characteristic diagram showing the relationship between the rotation angle of the planting case and the rotation angle of the planting claw (support case), FIG. 5 is a side view of the planting mechanism, and FIG. 6 is the planting claw support case. FIG. 7 is a vertical sectional side view of the part, and FIG. 7 is a side view showing a seedling planting device portion of the rice transplanter. (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 cases of the planting claw (3) in each rotation phase during the planting case (2) rotation. A planting claw drive mechanism of a rice transplanter configured such that the posture is determined, and the planting claws (3) alternately cut out the seedlings from the seedling stand (4) and plant them in the field. (11), the pair of intermediate gears (22), (23) and the final gear (20) are formed into non-circular gears with the same number of teeth and the same module that have been molded, and the specifications are (maximum pitch curve Radius Rmax) / (Minimum pitch curve radius Rm
in) = 1.3 to 1.5 (for each gear) Module m = (0.025 to 0.075) x axial distance Tool pressure angle α = 20 ° to 28 ° Addendum length = 1.2 m (module) or less The planting claw drive mechanism of the rice transplanter is characterized in that the bottom is configured as a tooth profile formed by a curve whose curvature continuously changes.