JPH01265809A - Planting claw driving mechanism of transplantation machine - Google Patents

Abstract

PURPOSE:To set the orbit of a transplantation claw tip in the form of a longitudinally oblong loop and to enable the transplantation leaving only a small dent of claw, by specifying various dimensions of sun gear, intermediate gears and final gear. CONSTITUTION:The sun gear 11, intermediate gears 22, 23 and final gear 20 are non-circular gears having the same teeth number and the same module. Each gear has the following dimensions. Ratio of (maximum pitch curve radius Rmax/minimum pitch curve radius Rmin)=1.3-1.5 (on each gear), module m=(0.025-0.075)X(distance between shafts), pressure angle of tool alpha=20-28 deg., addendum <=1.2m (module). The bottom of the gear forms a curve having continuously varying radius of curvature.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a system in which planting claws are attached to both ends of one rotationally driven planting case, so that two plantings can be performed with one rotation of the planting case. The present invention relates to the planting claw drive mechanism of the constructed rice transplanter.

[Conventional technology]

As the above-mentioned planting claw drive mechanism, for example, Japanese Patent Application Laid-Open No. 60-22
As shown in Japanese Patent No. 1009, the planting case is connected and fixed to a drive shaft that protrudes laterally from the planting case and is rotationally driven, and a sun gear is attached to the rotational center of the planting case. 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 a final gear is fixed to the support shaft that supports the planting claws, and the final gear is fixed to the sun gear. An intermediate gear is disposed between the final gear and the sun gear, the intermediate gear, and the outermost gear to form a gear train including gears of different diameters. There is a structure in which the posture of the planting claws is determined so that each planting claw alternately cuts out seedlings from a seedling stand and plants them in the field.

[Issues that development attempts to solve]

The above known means shifts a gear train consisting of a sun gear, an intermediate gear, and a final gear to a gear train including gears of different diameters,
While rotating the planting claw, it rotates at a non-uniform speed in the opposite direction to the revolution direction, gradually correcting the claw posture during the planting claw transfer process, and moving the tip of the planting claw from the bottom of the seedling stand. It is set in a vertically long loop shape that spans the field, but the loop of the claw tip trajectory is different from that of the conventional swinging planting method as shown in, for example, Japanese Patent Application Laid-Open No. 61-209519. Compared to the loop of the claw tip trajectory in the drive mechanism, the width was considerably wide from front to back.

Therefore, when planting is performed using a claw tip locus loop with a large front-to-back width, large claw marks are left at the planting site in the field, and the planted seedlings tend to fall or lift up.

Considering the disadvantages of the above-mentioned conventional means, it is found that circular eccentric gears and elliptical gears are used as gears of different diameters included in the gear train for causing the planting nails to rotate at inconstant speeds. The only changes to be made are the amount of eccentricity for eccentric gears, and the ratio of the major axis to minor axis for elliptical gears. There are few degrees of freedom, and this is a factor in the appearance of a claw tip locus loop with a large front-to-back width.

Therefore, the present inventor tried a method of first determining the loop of the nail tip trajectory and rotating the planted nail at an inconstant speed so as to satisfy this loop. In this case, the speed change characteristics required for the gear train cannot be satisfied with circular eccentric gears or elliptical gears.

Therefore, when the rotation angles of the input and output shafts of the gear are θ and φ, respectively, the free-form dθ-shaped pitch curve obtained by specifying the angular velocity ratio curve dφ □−[(θ) from the functional requirements is A non-circular gear is required.

However, here we will manufacture a non-circular gear like this.
A problem occurred.

In other words, if a non-circular gear is created with a normal involute tooth profile that does not satisfy the inconstant motion required to obtain the loop of the claw tip trajectory required by the planted claw drive mechanism of this mechanism, the radius of curvature of the pitch curve will be small. The occurrence of undercuts in the phase portion is unavoidable. For example, the value of the minimum radius of curvature of the pitch curve of the gear used in this example is approximately 10.2 mm.
When converted into an equivalent circular gear, the number of teeth is 10 in the tooth profile of the same module as in the example, and an undercut will inevitably occur. Of course, if the tooth profile module is made smaller, the problem of undercuts can be suppressed and smooth occlusion can be obtained. As a planting drive mechanism, it must be able to sufficiently withstand even when excessive torque is applied, such as when a foreign object is caught and the safety clutch in the planting claw drive mechanism is activated, and the planting drive mechanism is required to be as compact as possible. There are limits.

Furthermore, manufacturing a non-circular gear using a normal gear cutting device is expensive, and there are cost constraints.

An object of the present invention is to solve the above-mentioned problems in making the toe trajectory of a planting case rotating type planting claw drive mechanism vertically elongated.

[Failure to solve the problem]

The characteristic configuration for achieving the above object includes the sun gear,
When the intermediate gear and the final gear are molded into non-circular gears with the same number of teeth and the same module, the S element is module m - (0,025 to 0.075) X-axis distance tool The pressure angle α - 20'' to 28° is set to less than the tooth end length - 1.2 m (1,000 joules), and the tooth bottom is configured to have a tooth profile formed by a curve with a continuously changing curvature. There is a certain point.

[For production]

According to the above configuration, a large stress is concentrated particularly at the root of the tooth in the part where the radius of curvature of the pinch curve becomes small. By avoiding this, the pitch curve of each gear is relatively It can be set to any shape, and the characteristics of the inconstant rotation of the planting claw relative to the rotation of the planting case can be set with a large degree of freedom.

〔Effect of the invention〕

As a result, compared to the conventional method in which the planting claw was rotated at an inconstant speed using a gear train that introduced eccentric gears and elliptical gears, the planting claw tip axis mark was set in a more vertically elongated loop, and the claw trace was It is now possible to carry out small plantings.

In particular, by setting the specifications of each gear as described above, it is possible to avoid a decrease in strength due to undercuts while creating a relatively large module, and it is possible to use a small drive mechanism without the need to increase the width of the gear. It is now possible to perform the desired functions.

Furthermore, by forming such a non-circular gear into a molded gear, processing becomes easier and costs can be reduced.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings regarding a seedling planting device of 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 the planting case (2) is rotatably supported. 2 on both ends
A set of 1 claw (3) of planting potters is provided, and a planting case (
As 2) rotates, two sets of planting claws (3) move onto the seedling stand (4).
The structure is such that seedlings are alternately cut out from the seedling outlet (4a) at the lower end and planted in the field. A float (5) for leveling the ground and maintaining posture is provided at the bottom of the planting mission case (1), and these seedling planting devices are connected to the rear of the passenger vehicle (not shown) via parallel four-wheel links (6). It is connected so that it can be raised and lowered freely.

Next, to explain the structure inside the planting case (2) in detail, as shown in Fig. 1, the drive shaft (7) runs from the planting mission case (1) to the left and right along the horizontal axis (P). The planting case (2) is fixed to both ends of the protruding drive shaft (7), and a chain (9) is connected to a passive sprocket (8) provided at the center of the drive shaft (7). Power is being transmitted. The drive shaft (7) has a cylindrical shaft (1) fixed to the planting mission case (1).
0) has been inserted and inserted into the case (2),
A sun gear (
11) is fixed.

Next, to discuss the structure of the planting claw (3) and its attachment, as shown in Figures 1 and 6, a fixed shaft (12) is provided sideways protruding from both ends of the planting case (2). At the same time, a cylindrical support shaft (13) is freely and externally fitted onto this fixed shaft (12), and a planting nail support case (14) is fixed to this support shaft (13). The planting claw (-1) (3) is bolted and fixed to the tip of the planting claw support case (14), and a seedling pusher (15) that can move in and out along the planting claw (3) (provided, and the seedling pushing tool (15) is
The spring (16) acting on the rear end of the supporting rod (15a)
) is biased in the protruding direction. Further, a swinging arm (18) pivotally supported by a fulcrum shaft (17) is engaged with the rear end of the seedling pusher support rod (15a), and a cam follower connected from the swinging arm (18) Section (18a)
is the force l formed integrally with the fixed shaft (12), (19)
It acts in contact with the outer periphery of. While the planting claw (3) cuts out the seedlings from the seedling take-out port (4a) and brings them into the field, the cam follower part (18a) of the swinging arm (18) moves the size of the cam (18) as shown in the figure. Acting on the diameter part, the seedling pusher (15) is retracted against the spring (16),
When the planting claw (3) enters the field, the swinging arm (1)
When the cam follower part (18a) of 8) comes off from the large diameter part of the cam (19), the seedling pusher (15) is released from the spring (
16), and the seedlings held by the tips of the planting claws (3) and the seedling pusher (15) are pushed out and separated into the field and planted.

Next, to explain in detail the structure that determines the attitude of the planting claw (3), the final gear (20) is fixed to the support shaft (13) of the planting claw support case (14), and the final gear (20)
) and the sun gear (11), an intermediate shaft (21) is disposed and supported. A first intermediate gear (22) that meshes with the sun gear (11) and a second intermediate gear (23) that meshes with the final gear (20) are integrated into the intermediate shaft (22).
2) is fixed. And this sun gear (1
1), intermediate gears (22), (23), and final gear (
20) are configured as non-circular gears with the same number of teeth and the same module, and are manufactured by sintering molding.

The gear train made up of the gear group rotates the planting claw support case (14) once in the opposite direction at a non-uniform speed for each rotation (revolution) of the planting case (2), thereby rotating the planting claw ( 3)
The tip trajectory (S) of the planting nail is set in a vertically elongated loop shape up and down, and in order to obtain the planting nail tip trajectory (S) shown in the figure, the support shaft (13) of the planting nail support case (14) is It is necessary to rotate at an inconstant speed with the characteristics shown in FIG. 4, and for this reason, the gear group is configured as a non-circular gear.

In this case, each gear (11), (22), (23>,
The degree of non-circularity of (20) is.

In addition, the specifications of the gear train and gears are as follows: The distance between the axes of the sun gear (11) and the first intermediate gear (22) -
Approximately 40+nm Distance between the axes of the second intermediate gear (23) and the final gear (20) -
Approximately 40mm Module m = 2.0 Tool pressure angle α - 25° End height - 1.2m (module) or less, and the tooth bottom is formed into a curve with a continuously changing curvature. In addition, the tooth tip should have an appropriate radius (see Figure 3). Incidentally, the broken line in Figure 3 shows the case where a standard involute tooth profile is assigned to a non-circular pitch curve, which has a drawback in terms of strength. .

The above gear specifications are just an example, but module m is module m - (0,025 to C1,075) from the perspective of occlusal strength. Angle α=20° to 28° is preferred.

In addition, each gear (11), (22>, (23), (2
When designing a specific tooth profile for 0>, the computer determines the pitch curve of each gear dθ obtained from the angular velocity ratio curve □=f(θ) to achieve the desired inconstant rotation. The teeth are divided by giving the desired module, and the tooth profile is modified by the means proposed here to address the reduction in strength due to undercuts.
Finally, the tooth profile of each gear is determined, and based on this, a template for the sintering mold is manufactured. In addition to the sintering mold, other methods such as fine blanking may be used as the molding method.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional plan view of the planting claw drive mechanism according to the present invention, Fig. 2 is a side view showing the entire gear train and a part thereof, and Fig. 3 is a side view showing a part of the tooth profile of the non-circular gear. Figure 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), Figure 5 is a side view of the planting mechanism, and Figure 6 is the planting claw support. FIG. 7 is a side view showing the seedling planting device of the rice transplanter.

Claims (1)

[Claims] A planting case (2) is connected and fixed to a drive shaft (7) that protrudes laterally from a planting transmission case (1) and is rotationally driven, and the rotation inside the planting case (2) is fixed. Sun gear (
11) is arranged in a fixed state with respect to the planting mission case (1), and a pair of planting claws (3) are provided at both ends of the planting case (2), and the planting claws (3) are arranged in a fixed state on the planting mission case (1). A final gear (20) is fixed to a supported support shaft (13), intermediate gears (22) and (23) are arranged between the sun gear (11) and the final gear (20), and Sun gear (11), intermediate gears (22), (23) and final gear (
20) into a gear train including gears of different diameters, and both planting claws (
3), and each planting claw (3) is placed on the seedling stand (4).
) is a planting claw drive mechanism of a rice transplanter configured to alternately cut out seedlings and plant them in a field, the mechanism comprising the sun gear (11), intermediate gears (22), (23) and the final gear (
20) into a molded non-circular gear with the same number of teeth and the same module, and its specifications are as follows: {maximum pitch curve radius Rmax}/{minimum pitch curve radius Rmin}=
1.3~1.5 (for each gear) module m = (0.0
25 to 0.075) x center distance tool pressure angle α = 20°
~28° A rice transplanter characterized in that the tooth end length is set to 1.2 m (module) or less, and the tooth bottom is configured in a tooth profile formed by a curved line with a continuously changing curvature. Attached claw drive mechanism.