JP2015047153A - Rice transplanter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rice transplanter for improving a phase difference by providing a torque for canceling a torque fluctuation that occurs at planting arm axis to level the torque fluctuation, thereby optimizing a trajectory of a planting claw and preventing defective planting.SOLUTION: A rice transplanter for delivering power via an inconstant speed mechanism to a planting arm axis supporting a rotary case includes a torque leveling mechanism for providing a torque that cancels a torque fluctuation resulting from the inconstant speed mechanism. The torque leveling mechanism provided in a power delivering path for delivering the power to the planting arm includes: a crank portion which is a crank-like formed part of an axis that rotates at a twice as many number of rotation as that of the planting arm; and a spring attached to the crank portion. The spring provides the torque, and is attached by means of a hook which is formed of a material different from the spring and is engageable on an outer circumference of the crank portion.

Description

  The present invention relates to a rice transplanter.

With traditional rice transplanters, if the planting claw tip trajectory is set to be nearly vertical near the bottom dead center based on dense planting, the speed at which the planting claw escapes from the field is slow in the sparse planting state. Therefore, a phenomenon that the planted seedling is pushed forward tends to occur. On the contrary, based on sparse planting, if the locus of the tip of the planting claw is set to be almost vertical near the bottom dead center, the planting claw will be pushed back into the field in the dense planting state. , And floating seedlings are likely to occur due to loose seedlings and mud.
For this reason, a non-constant speed mechanism is provided for sparse planting so that the planting claws escape and move more quickly from the field with reference to the dense planting state, and one of the rotary planting arm shafts that support the planting claws. There is a method of changing the angular velocity (rotational speed) during rotation.

  Patent Document 1 discloses a technique for providing a speed change as follows by providing an inconstant speed transmission mechanism between a planting mission case and a planting arm shaft and changing an angular velocity during one rotation. . That is, when a seedling is taken, a fast section is provided immediately after planting, and a slow section is provided before seedling and before planting, thereby realizing a good seedling harvesting operation and planting operation.

Japanese Patent Laid-Open No. 07-163216

Since the inconstant speed transmission mechanism accelerates and decelerates the angular velocity during one rotation of the rotating shaft, torque fluctuation (load fluctuation) applied to the rotating shaft increases. Repeated twisting and untwisting of the rotating shaft causes backlash of gears constituting the driving system or backlash due to gaps generated between parts during manufacturing of the driving system and drive system rotation unevenness due to driving system twisting. As a result, rotational fluctuations increase and the acceleration / deceleration phase shifts, leading to poor planting.
Therefore, the present invention provides a torque that cancels the torque fluctuation generated in the planting arm shaft, leveles the torque fluctuation, and improves the phase shift, thereby optimizing the locus of the planting claw and preventing poor planting. Provide rice transplanters.

  The first embodiment of the present invention is a rice transplanter that transmits power to a planting arm shaft that supports a rotary case via an inconstant speed mechanism, and applies torque that cancels torque fluctuations caused by the inconstant speed mechanism. A torque leveling mechanism that is provided in a power transmission path that transmits power to the planting arm shaft, and is a shaft that rotates at twice the number of rotations of the planting arm shaft. A crank portion formed in a crank shape, and a spring attached to the crank portion, the torque is applied by the spring, and the spring is a separate member from the spring, and the crank It is attached to the outer periphery of the part via a hook that can be locked.

  The hook has a curved surface portion that curves according to the outer peripheral shape of the crank portion, and a locking portion that extends from the curved surface portion toward the spring side and through which the end portion of the spring can be inserted. A plurality of planar portions formed in order, and the spring is fixed to the hooks by being sequentially inserted into a plurality of engaging portions provided on the planar portion of the hook.

  A second embodiment of the present invention is a rice transplanter that transmits power to a planting arm shaft that supports a rotary case via an inconstant speed mechanism, and the planting arm shaft is chained in a planting chain case. And a torque leveling mechanism for applying a torque that counteracts torque fluctuations caused by the non-constant speed mechanism is provided in the planting chain case, and the torque leveling mechanism is provided in the planting chain case. The chain driving force is changed by changing the chain tension.

  According to the present invention, the torque fluctuation generated by the inconstant speed mechanism is leveled, the rotational fluctuation is suppressed, and the phase shift is improved, so that the locus of the planting claw can be optimized and poor planting can be prevented. .

It is a side view of a rice transplanter. It is a skeleton figure of a planting drive part. It is a partial cross section figure of the planting bevel case in which a torque leveling mechanism is provided. It is a figure which shows the housing part of a planting bevel case. It is a figure which shows the attachment structure of a torque leveling mechanism. It is a figure which shows the fixing method to the hook of a coil spring. It is a figure which shows the method to install in a housing part the coil spring and the hook integrated with the coil spring. It is a figure which shows another embodiment of a hook. It is explanatory drawing of the torque provided by a torque leveling mechanism. It is a figure which shows the torque fluctuation which arises in the planting arm axis | shaft driven by an inconstant speed mechanism, the leveling torque provided by a torque leveling mechanism, and these synthetic torques. It is a figure which shows the example of arrangement | positioning in the case of providing a unit clutch in a planting horizontal axis. It is a figure which shows the example of arrangement | positioning in the case of providing a unit clutch in a planting horizontal axis. It is a figure which shows the example of arrangement | positioning in the case of providing a unit clutch in a planting horizontal axis. It is a figure which shows the example of arrangement | positioning in the case of providing a unit clutch in a planting vertical axis | shaft. It is a skeleton figure of a planting drive part at the time of using a chain drive type thing for power transmission to a planting part. It is a figure which shows embodiment in the case of providing a torque leveling mechanism in a chain. It is a figure which shows another embodiment of a torque leveling mechanism.

The rice transplanter 1 will be described with reference to the accompanying drawings.
The rice transplanter 1 performs planting work by the planting unit 5 while driving the front wheel 3 and the rear wheel 4 with the power of the engine 2. The power from the engine 2 is transmitted to the front wheel 3 and the rear wheel 4 through the transmission case 6, and to the planting unit 5 through the transmission case 6 and the stock change device 9, respectively.
The planting unit 5 includes a planting center case 10, a planting bevel case 11, a rotary case 12, a planting arm 13, a seedling table 14, and a plurality of floats 15.

FIG. 2 is a transmission system diagram regarding the planting drive of the planting unit 5. Although FIG. 2 shows one planting unit, the other planting units are similarly configured.
The planting horizontal shaft 20 branched from the planting center case 10 is transmitted to the planting vertical axis 22 in the planting bevel case 11 via the bevel gears 21a and 21b. A torque limiter 26 is attached to the planting vertical axis 22, and power transmission is cut off when a predetermined load or more is applied to the planting vertical axis 22. And it is transmitted to the unit clutch 24 from the planting longitudinal axis 22 via the inconstant speed bevel gears 23a and 23b.
Power is transmitted to the planting arm shaft 25 when the unit clutch 24 is connected according to the connection / disconnection of the unit clutch 24. On the other hand, when the unit clutch 24 is in a disconnected state, power is not transmitted to the planting arm shaft 25.

  The planting arm shaft 25 extends into the rotary case 12 provided on the left and right of the planting bevel case 11 and is fixed to the rotary case 12. By rotating the rotary case 12, the sun gear 30 fixed to the planting bevel case 11 is transmitted to the planetary gear 32 via the intermediate gear 31. And it is transmitted to the planting arm 13 fixed to the planetary gear 32 via the rotor arm shaft 33, and the planting claw 34 is rotated together with the rotary case 12, so that the seedling can be taken from the seedling stage 14 and planted. .

[Inconstant speed mechanism]
An inconstant speed mechanism included in the inter-plant change device 9 for transmitting power to the planting unit 5 and an inconstant speed mechanism including the inconstant speed bevel gears 23a and 23b in the planting bevel case 11 of the planting unit 5. Thus, the planting arm shaft 25 rotates at an unequal speed.
That is, when the planting claw 34 takes the seedling from the seedling stage 14 and when the planting claw 34 is quickly pulled out from the field after planting the seedling and the seedling remaining on the planting claw 34 is shaken off, the rotary case 12 rotates. The rotational speed of the rotary case 12 is reduced before the seedlings are planted in the field and when the planting claws 34 are inserted into the seedling stage 14 while speeding up the driving.
In this way, power is transmitted to the planting arm shaft 25 through the inconstant speed mechanism, and is rotationally driven with periodic acceleration / deceleration. Thereby, the torque fluctuation resulting from the inconstant speed motion generate | occur | produces in the planting arm axis | shaft 25. Specifically, since acceleration / deceleration is performed with reference to the time of seedling and planting of each planting claw 34, torque fluctuations caused by non-constant speed motion are two times during one rotation of the rotary case 12. Periodic fluctuations with a peak of times.
Note that, depending on the number of stocks set by the stock change device 9 during dense planting, the power may be transmitted at a constant speed, and the power is not always transmitted at a non-uniform speed.

  In addition, the planting claw 34 scrapes off the seedling from the seedling mounting table 14 in a slanted posture in a side view, and then the planting claw is in a posture close to the vertical and heads to the field, and after having descended, it is necessary to turn upward. Therefore, the sun gear 30, the intermediate gear 31, and the planetary gear 32 in the rotary case 12 are non-circular and eccentric. In addition, for the same reason as the planting arm shaft 25, the rotor arm shaft 33 supporting the planting arm 13 is also rotated at an inconstant speed with respect to the rotary case 12 by an inconstant speed mechanism.

[Torque leveling mechanism]
As shown in FIG. 2, a crank-spring type torque leveling mechanism 40 is provided on the planting longitudinal axis 22 in the planting bevel case 11. The planting vertical axis 22 has a crank portion 41 formed by bending in a crank shape, and a coil spring 42 is attached to the crank portion 41.
As shown in FIGS. 3 and 4, the planting bevel case 11 includes a housing portion 45 that houses the torque leveling mechanism 40 and a lid 46 that closes an opening provided in the housing portion 45.

  The housing part 45 is provided at a position where the crank part 41 is formed on the planting longitudinal axis 22, that is, at a position (rear part side) near the planting arm shaft 25. The housing portion 45 is integrally provided as a part of the planted bevel case 11 by being integrally formed. The housing part 45 has a shape protruding upward from the upper surface of the planting bevel case 11. This is to avoid interference with the rotary case 12 because the planting arm shaft 25 is provided from the rear part of the planting bevel case 11 toward both sides and the rotary case 12 is supported.

  On one side surface of the housing part 45, an opening 45a used for installation, replacement, repair, etc. of the torque leveling mechanism 40 is provided. The opening 45a is an opening provided on the entire side surface (left side) of the housing part 45, and is accessible inside the housing part 45 through the opening 45a. The opening 45a is provided so that it can be opened and closed. Specifically, by fixing the sheet metal lid 46 with a bolt or the like, the opening 45a is closed and the inside of the planting bevel case 11 is sealed.

  The torque leveling mechanism 40 includes a crank part 41 of the planting longitudinal axis 22, a coil spring 42 that is attached to the crank part 41 and gives elastic force to the crank part 41, and a hook for attaching the coil spring 42 to the crank part 41. 43 is comprised. One end (lower end) of the coil spring 42 is attached to the crank portion 41 via a hook 43. The other end (upper end) of the coil spring 42 is attached to the planting bevel case 11 via a spring hook 47 provided at the upper end of the housing part 45. Thereby, the torque leveling mechanism 40 is accommodated in the housing part 45.

With reference to FIGS. 5 to 7, a structure for attaching the torque leveling mechanism 40 to the housing portion 45 of the planting bevel case 11 will be described. 5 to 7, illustration of the planting bevel case 11 is omitted for convenience of explanation.
The coil spring 42 is a general coil spring configured by winding a metal wire in a cylindrical shape, and an upper end extending upward is bent and a spring hook 44 is provided, and a lower end is wound in a cylindrical shape. Is maintained. A hook 43 is fixed to the lower end of the coil spring 42.

As shown in FIG. 6, the hook 43 is a hook-shaped metal fitting formed by bending a single metal plate. The hook 43 has a curved surface portion 43a having a curved shape that can be locked to the outer periphery of the crank portion 41, and a locking portion that extends from the curved surface portion 43a toward the coil spring 42 and through which an end of the coil spring 42 can be inserted (FIG. 6). (A) is configured by a flat portion 43b provided with a plurality of locking holes and a locking groove in FIG. 6 (b). The coil spring 42 is fixed to the hook 43 by inserting the end portion into the engaging portion formed on the flat surface portion 43 b in order while rotating the coil spring 42.
The contact with the crank portion 41 in the side surface cross section of the curved surface portion 43a is about half of a perfect circle, and the upper side is opened by the shaft diameter of the crank portion 41 so that the crank portion 41 can be hooked from below. Formed into a shape.

  As shown in FIG. 7, the spring hook 47 has an H shape in which a notch is provided from the center of two opposite sides of the rectangular plate to the center of the plate. The notch of the spring hook 47 is formed to a size that allows the spring hook 44 of the coil spring 42 to be hooked.

When the torque leveling mechanism 40 is attached, that is, when the coil spring 42 to which the hook 43 is fixed is locked to the crank portion 41 and the spring hook 47, the hook 43 fixed to the lower end of the coil spring 42 is hung on the crank portion 41, A spring hook 44 at the upper end of the coil spring 42 is hooked on a spring hook 47 of the housing part 45.
The assembling work of the torque leveling mechanism 40 is performed through the opening 45a with the lid 46 removed and the housing 45 of the planting bevel case 11 opened.

With the configuration as described above, the cost can be reduced without greatly increasing the number of parts when the torque leveling mechanism 40 is introduced into an existing rice transplanter.
Further, by providing an opening 45a that opens on one side of the housing 45 and the opening 45a can be opened and closed by the lid 46, the assembly work can be easily performed through the opening 45a during assembly. In addition to improving workability, the lid 46 can be removed during maintenance to easily perform maintenance through the opening 45a, thereby improving maintainability.

When the torque leveling mechanism 40 is assembled, the spring hook 44 of the coil spring 42 and the hook 43 integrated with the coil spring 42 can be easily installed by being hooked on the spring hook 47 and the crank portion 41, respectively. Realize the sex.
Furthermore, a hook 43 as a separate member is provided at the connecting portion between the coil spring 42 and the crank portion 41, and the coil spring 42 and the hook 43 are integrally fixed, so that the influence of the rotational motion of the crank portion 41 is directly affected. The coil spring 42 is not given to the coil spring 42 and the life of the coil spring 42 can be extended.

  The hook 43 is preferably made of a material having a low friction coefficient, wear resistance, and surface pressure resistance, such as a material generally used for a bush. By using a bearing material such as a bush for the hook 43 in this way, wear due to friction with the crank portion 41 can be prevented, and high durability can be ensured.

  As the planting longitudinal axis 22 rotates, the crank portion 41 rotates at a position eccentric from the center of rotation of the planting longitudinal axis 22, and the length of the coil spring 42 changes to generate an elastic force in the coil spring 42. Thus, torque is generated in conjunction with the rotation of the planting vertical axis 22. The elastic force generated in the coil spring 42 is applied as torque to the planting arm shaft 25 via the planting longitudinal axis 22.

  The mechanism for generating torque in conjunction with the rotation of the planting vertical axis 22 is not limited to the crank / spring mechanism using the crank portion 41 and the coil spring 42, and the cam rotating with the planting vertical axis 22 and the cam A cam-spring type mechanism constituted by a leaf spring that imparts elastic force can also be employed.

The torque applied by the torque leveling mechanism 40 will be described in detail with reference to FIG.
In addition, FIG. 8 has shown the figure at the time of seeing from the front, and the planting vertical axis | shaft 22 rotates clockwise in illustration. Thereby, the crank part 41 rotates clockwise with the rotation axis of the planting vertical axis 22 as the rotation center.

  As shown in FIG. 8A, when the crank portion 41 is located on the left side, that is, on the side where the contraction force by the coil spring 42 is in the same direction as the rotation direction of the planting longitudinal axis 22, the elastic force of the coil spring 42 is planted. Torque is generated in the same direction as the rotation direction of the vertical axis 22. The torque generated on the planting vertical axis 22 via the crank portion 41 is transmitted to the planting arm shaft 25 via the inconstant speed bevel gears 23a and 23b. At this time, torque to the acceleration side is applied to the planting arm shaft 25.

  As shown in FIG. 8B, when the crank portion 41 is located on the right side, that is, on the side where the contraction force by the coil spring 42 is opposite to the rotation direction of the planting longitudinal axis 22, the elastic force of the coil spring 42 is planted. Torque is generated in the direction opposite to the rotation direction of the attached vertical axis 22. The torque generated on the planting vertical axis 22 via the crank portion 41 is transmitted to the planting arm shaft 25 via the inconstant speed bevel gears 23a and 23b. At this time, torque to the deceleration side is applied to the planting arm shaft 25.

Further, when the crank portion 41 rotates around the planting longitudinal axis 22, the elastic force generated in the crank portion 41 as the coil spring 42 expands and contracts is transmitted to the planting arm shaft 25 as a periodic torque. Specifically, a curve close to a sine curve is drawn according to the position and angle of the spring hook 47 that is the fixed end of the coil spring 42 and the crank portion 41, that is, the position and angle of the crank portion 41 with respect to the planting longitudinal axis 22. A torque that fluctuates in the direction is generated.

As shown in FIG. 9, the direction of the torque fluctuation generated by the inconstant speed mechanism is canceled by matching the period of torque generated by the torque leveling mechanism 40 with the period of torque fluctuation generated in the planting arm shaft 25 by the inconstant speed mechanism. In addition, torque is generated by the torque leveling mechanism 40 (so as to have an opposite phase in the drawing).
At this time, since the planting vertical axis 22 including the crank portion 41 rotates at twice the number of rotations of the planting arm shaft 25, the planting arm shaft 25 is rotated two times during one rotation of the planting arm shaft 25. Torque for the period is generated. In other words, the torque leveling mechanism 40 can generate a torque that cancels out a periodic torque fluctuation having two peaks that occur during one rotation of the rotary case 12 via the inconstant speed mechanism, and equalizes the torque. it can.
In this way, by adjusting the cycle of the torque leveling mechanism 40 to the cycle of torque fluctuation by the inconstant speed mechanism, torque is synthesized to suppress torque fluctuation caused by the inconstant speed mechanism.

  In the present embodiment, the equalized torque in the opposite phase is applied to the torque fluctuation caused by the inconstant speed mechanism. However, if the torque fluctuation is effectively suppressed, the torque fluctuation is completely reversed. It may not be the phase leveling torque. For example, it is possible to cancel the torque fluctuation by applying a leveling torque that is appropriately delayed by 30 ° or 45 ° with respect to the torque fluctuation. In this case, it can be set as appropriate by changing the timing of the torque generating mechanism provided on the planting vertical axis 22. In the present embodiment, the application timing of the leveling torque can be adjusted by changing the phase of the crank portion 41 relative to the planting longitudinal axis 22 when the coil spring 42 is attached to the crank portion 41.

  As described above, the torque leveling mechanism 40 applies a smooth torque having the same cycle (two cycles for one rotation of the rotary case 12) as the cycle of the torque variation generated by the inconstant speed mechanism, thereby leveling the torque variation. Thus, the phase shift of the planting arm shaft 25 can be improved. As a result, the planting arm shaft 25 can smoothly rotate at a non-uniform speed without twisting or rattling, stabilizing the locus of the planting claw 34 during high-speed rotation, and preventing poor planting.

  The torque leveling mechanism 40 is provided for each planting unit in which the planting arm shaft 25 is provided. In other words, since the leveling torque cancels out in each unit with the torque fluctuation generated by the acceleration / deceleration of the rotary case 12, the torque fluctuation does not go back to the upstream side of the transmission system. it can.

  The housing portion 45 in the present embodiment is formed in a shape protruding upward, so that the torque leveling mechanism 40 is located near the planting arm shaft 25 of the planting vertical axis 22 without interfering with the rotation of the rotary case 12. Provided. That is, the torque fluctuation can be leveled effectively by providing the torque leveling mechanism 40 in the vicinity of the site where the occurrence of the shakiness due to the non-uniform speed motion is likely to occur.

The opening of the housing portion is not limited to the side surface, and can be provided on the upper surface. For example, in order to ensure accessibility from the upper surface, the housing portion is provided integrally with the planting bevel case 11, and the housing lower portion whose upper surface is open and the planting bevel case 11 are provided as separate members. Further, it is possible to apply a two-part configuration with the upper portion of the housing provided so as to close the opening at the lower portion of the housing and project upward from the lower portion of the housing.
In this case, it is possible to fix the spring hook 47 inside the upper part of the housing, and to make the upper part of the housing function as a lid for closing the opening of the housing part. It is also possible to open the upper part of the housing and close it with a separate lid. In this case, it is preferable to provide a spring hook 47 that hooks the spring hook 44 of the coil spring 42 on the lid side in consideration of workability during assembly.

  Furthermore, the length of the coil spring 42 can be adjusted by allowing the spring hook 47 to move in the vertical direction within the housing portion 45 by using a clutch pin, an arm, or the like. That is, the spring force of the coil spring 42 can be adjusted by changing the position of the spring hook 47, and the leveling torque to be applied can be adjusted.

As a hook for attaching the coil spring 42 to the crank portion 41, a U-shaped hook 50 as shown in FIG.
The hook 50 has a flat plate curved in a U shape, and a hook portion 51 locked to the crank portion 41 from below, and a pin 52 fixed through the flat portion of the hook portion 51 curved in a U shape. And a frame 53 that is rotatably provided on the outer periphery of the pin 52. When such a hook 50 is employed, a spring hook 54 is provided at the lower end of the coil spring 42 similarly to the upper end. In the center of the top 53, a groove for hooking the spring hook 54 is provided.

  Although the power transmission path to the planting part 5 in the above-described embodiment mainly uses gears, the power branching from the planting center case 10 can be transmitted to each planting unit. For example, a chain drive type using a sprocket and a chain can be similarly applied.

Further, when a chain drive type is adopted for power transmission from the planting horizontal shaft 20 to the rotary case 12 of each unit, instead of the planting bevel case 11 that houses the planting vertical axis 22 and the bevel gears 23a and 23b, planting is performed. A drive sprocket fixed to the attached horizontal shaft 20, a sprocket fixed to the planting arm shaft 25, and a planted chain case that accommodates a chain wound around these sprockets are provided.
In such a configuration, the torque leveling mechanism 40 is provided on the planting horizontal shaft 20, that is, a part of the planting horizontal shaft 20 is formed in a crank shape and the crank portion 41 is provided, and the hook 43 is provided on the crank portion 41. The structure which attaches the coil spring 42 via can be employ | adopted. Alternatively, a shaft (option shaft) that rotates at twice the planting arm shaft 25 is added to the planting arm shaft 25, and the torque leveling mechanism 40 is similarly provided on the option shaft. Similar effects can be obtained. Furthermore, a follower sprocket is added to the chain in the planted chain case, a crank portion 41 is provided on the support shaft of the follower sprocket, and a coil spring 42 is similarly disposed via the hook 43, whereby torque is applied to the support shaft. A leveling mechanism 40 may be provided.

[Unit clutch arrangement]
In the above embodiment, the unit clutch 24 is provided between the planting longitudinal axis 22 and the planting arm shaft 25, but the unit clutch is preferably provided upstream in the power transmission path of the torque leveling mechanism 40. preferable. By providing on the upstream side, the torque leveling mechanism 40 operates according to the connection of the unit clutch. That is, since the leveling torque does not act when the unit clutch is disengaged, the leveling torque according to the number of operating stripes can be appropriately applied.

  FIG. 11 to FIG. 13 show examples of arrangement when the unit clutch 60 is provided on the planting horizontal shaft 20. The unit clutch 60 is provided on a bevel gear 21 a that transmits power from the planting horizontal shaft 20 to the planting vertical axis 22. That is, the unit clutch 60 can disconnect the power transmission to the torque leveling mechanism 40 provided on the planting vertical axis 22 by connecting and disconnecting the power transmission between the planting horizontal axis 20 and the planting vertical axis 22. It is.

The unit clutch 60 shown in FIG. 11 will be described.
A bevel gear 21a is supported on the planting horizontal shaft 20 so as to be relatively rotatable. The bevel gear 21a has a cylindrical portion that extends along the planting longitudinal axis 22 on the back side of the gear forming portion, and a movable clutch 61 is slidably supported on the outer periphery of the cylindrical portion via a spline. . A cam 62 is provided at the end of the movable clutch 61. A fixed cam 63 that can mesh with the cam 62 is fixed to the planting horizontal shaft 20. The fixed cam 63 is supported by the planting horizontal shaft 20 so as not to be relatively rotatable. A spring 64 is interposed between the bevel gear 21 a and the movable clutch 61, and the cam 62 of the movable clutch 61 and the fixed cam 63 of the planting horizontal shaft 20 are pressed by the elastic force of the spring 64 in a direction to engage with each other. .
A flange 65 projects from the outer periphery of the movable clutch 61. When the clutch pin 66 comes into contact with the flange 65, the spring 64 is compressed and the cam 62 of the movable clutch 61 moves away from the fixed cam 63. In other words, the clutch pin 66 is configured to operate the connection and disconnection of the unit clutch 60.

Next, the unit clutch 60 shown in FIG. 12 will be described.
A bevel gear 21a is supported on the planting horizontal shaft 20 so as to be relatively rotatable. The bevel gear 21a has a cylindrical portion that extends along the planting longitudinal axis 22 on the back side of the gear forming portion, and a movable clutch 61 is slidably supported on the outer periphery of the cylindrical portion via a spline. . Further, the end portion of the cylindrical portion of the bevel gear 21 a comes into contact with a retaining ring 67 fixed to the planting horizontal shaft 20. A cam 62 is provided at the end of the movable clutch 61. A fixed cam 63 that can mesh with the cam 62 is fixed to the planting horizontal shaft 20. The fixed cam 63 is supported by the planting horizontal shaft 20 so as not to be relatively rotatable. A spring 64 is interposed between the bevel gear 21 a and the movable clutch 61, and the cam 62 of the movable clutch 61 and the fixed cam 63 of the planting horizontal shaft 20 are pressed by the elastic force of the spring 64 in a direction to engage with each other. .
A flange 65 projects from the outer periphery of the movable clutch 61. When the clutch pin 66 comes into contact with the flange 65, the spring 64 is compressed and the cam 62 of the movable clutch 61 moves away from the fixed cam 63. In other words, the clutch pin 66 is configured to operate the connection and disconnection of the unit clutch 60.

Next, the unit clutch 60 shown in FIG. 13 will be described.
A bevel gear 21a is supported on the planting horizontal shaft 20 so as to be relatively rotatable. The bevel gear 21a has a cylindrical portion extending along the planting vertical axis 22 on the gear forming portion side and extending toward the bevel gear 21b on the planting vertical axis 22 side, and a movable clutch 61 is provided on the outer periphery of the cylindrical portion. It is slidably supported through a spline. Further, the back surface portion of the gear forming portion of the bevel gear 21 a abuts on a retaining ring 68 fixed to the planting horizontal shaft 20. A cam 62 is provided at the end of the movable clutch 61. A fixed cam 63 that can mesh with the cam 62 is fixed to the planting horizontal shaft 20. The fixed cam 63 is supported by the planting horizontal shaft 20 so as not to be relatively rotatable. A spring seat 69 is fixed to the outer peripheral side of the tubular portion of the bevel gear 21 a, and a spring 64 is interposed between the spring seat 69 and the movable clutch 61. The cam 62 of the movable clutch 61 and the fixed cam 63 of the planting lateral shaft 20 are pressed in a direction to be engaged with each other by the elastic force of the spring 64.
A flange 65 projects from the outer periphery of the movable clutch 61. When the clutch pin 66 comes into contact with the flange 65, the spring 64 is compressed and the cam 62 of the movable clutch 61 moves away from the fixed cam 63. In other words, the clutch pin 66 is configured to operate the connection and disconnection of the unit clutch 60.

  FIG. 14 shows an arrangement example when the unit clutch 70 is provided on the planting vertical axis 22. The unit clutch 70 is provided in the transmission path from the bevel gear 21b to the torque limiter 26. That is, the unit clutch 70 is disposed upstream of the torque leveling mechanism 40 provided on the planting vertical axis 22 and upstream of the torque limiter 26. Thereby, the unit clutch 70 cuts off the power transmission to the torque leveling mechanism 40 provided on the planting vertical axis 22 by connecting and disconnecting the power transmission between the planting horizontal axis 20 and the planting vertical axis 22. Is possible.

The unit clutch 70 shown in FIG. 14 will be described.
A cylindrical member 71 having a cam that can mesh with the clutch of the torque limiter 26 is supported on the outer periphery of the planting longitudinal axis 22 so as not to be relatively rotatable. A bevel gear 21b is supported on the outer periphery of the cylindrical member 71 so as to be relatively rotatable, and a movable clutch 72 is slidably supported via a spline. A cam 73 is provided at the end of the movable clutch 72. A fixed cam 74 that can mesh with the cam 73 is fixed to the bevel gear 21b. A spring 75 is interposed between the movable clutch 72 and the cylindrical member 71, and the cam 73 of the movable clutch 72 and the fixed cam 74 of the bevel gear 21 b are pressed by the elastic force of the spring 75 in a meshing direction.
A flange 76 projects from the outer periphery of the movable clutch 72. When the clutch pin 77 comes into contact with the flange 76, the spring 75 is compressed and the cam 73 of the movable clutch 72 moves away from the fixed cam 74. That is, the clutch pin 77 is configured to operate the connection and disconnection of the unit clutch 70.

[Chain drive type]
Next, a torque leveling mechanism when a chain drive type using a sprocket and a chain is adopted as the power transmission mechanism for transmitting the power branched from the planting center case 10 to each planting unit will be described.
FIG. 15 shows a transmission system diagram when a chain drive type is used for the planting drive of the planting unit 5. In the embodiment shown in FIG. 15, power is transmitted from the planting horizontal shaft 20 to the safety clutch 81 in the planting chain case 80 and transmitted to the sprocket 82 fixed to the safety clutch 81. A chain 85 is wound around the sprocket 82 and a sprocket 84 provided in the unit clutch 83 on the rotary case side. When the unit clutch 83 is connected according to the connection / disconnection, the power is transmitted to the planting arm shaft 25 as a chain driving force via the sprocket 84 and the chain 85.

As shown in FIG. 16, the chain driving force can be changed by increasing or decreasing the tension of the chain 85 by the torque leveling mechanism 90 that changes the tension of the chain 85. Thereby, leveling torque is applied to the planting arm shaft 25.
The torque leveling mechanism 90 is provided on the same level as the leveling sprocket 91 and sprocket 82 having the same number of teeth as the drive-side sprocket 82, and is wound around the driving sprocket 92 and leveling sprocket 91 having the same number of teeth as the sprocket 82. A chain 93 to be rotated, a disc shaft of the leveling sprocket 91, a crankshaft 94 fixed at a position eccentric from the center thereof, a rod 95 rotatably supported by the crankshaft 94, and a center at the other end of the rod 95 A tension sprocket 97 to which the shaft 96 is connected is provided. The tension sprocket 97 is a driven sprocket that is supported so as to be rotatable relative to the central shaft 96, can contact the chain 85 wound around the sprockets 82 and 84, and rotates as the chain 85 rotates. .

A pair of guides 98 are provided on both sides of the central shaft 96 of the tension sprocket 97, and the tension sprocket 97 is regulated so as to move linearly.
When the leveling sprocket 91 that receives the driving force from the chain 93 rotates, the crankshaft 94 rotates, and the position of the tension sprocket 97 changes via the rod 95. At this time, the tension sprocket 97 is linearly moved by the guide 98 to reciprocate in the direction of increasing (tensioning) the tension of the chain 85 and the direction of reducing (releasing) the chain 85, thereby driving the chain 85. Change power regularly. Thus, the leveling torque can be applied to the planting arm shaft 25 by changing the chain driving force of the chain 85.
As described above, by arranging the torque leveling mechanism 90 in the planting chain case 80, it is possible to improve durability and maintainability while ensuring mudproofing and waterproofing without increasing the size of the device configuration. .

The mechanism for reciprocating the tension sprocket 97 is not limited to the crank type described above, and a cam type as shown in FIG. 17 may be used.
As shown in FIG. 17, a cam 100 fixed to the disk portion of the leveling sprocket 91, a tappet 101 that makes contact with the cam surface of the cam 100 and reciprocates, and a center shaft 96 of the tappet 101 and the tension sprocket 97 And a spring 102 to be connected. The cam 100 has a cam surface formed by a semicircle and a semi-ellipse, and is configured such that the tappet 101 reciprocates once when the cam 100 makes one rotation.

The position where the tension is changed by the tension sprocket 97 is not limited to the arrangement in which the tension is changed from the inside as shown in FIGS. 16 and 17, and the arrangement in which the tension is changed from the outside of the chain 85 may be used. You may arrange | position in the downstream of the drive side sprocket 82. FIG.
The sprocket for driving the leveling sprocket 91, that is, the chain 93 wound around the leveling sprocket 91 may be the sprocket 84 on the planting arm side.
In addition, a belt drive system using a pulley and a belt can be adopted as well as a chain drive system using a sprocket and a chain, and even in the case of a belt drive system, a torque leveling mechanism can be provided as in the chain drive system.

  1: Rice transplanter, 5: Planting part, 9: Stock changer (non-uniform speed mechanism), 11: Planting bevel case, 12: Rotary case, 20: Planting horizontal axis, 21a, 21b: Bevel gear, 22: Planting vertical axis, 23a / 23b: non-constant speed bevel gear (non-constant speed mechanism), 24: unit clutch, 25: planting arm shaft, 40: torque leveling mechanism, 41: crank part, 42: coil spring, 43: Hook, 43a: curved surface portion, 43b: flat surface portion, 45: housing portion, 46: lid

Claims (3)

A rice transplanter that transmits power to a planting arm shaft that supports a rotary case via an inconstant speed mechanism,
A torque leveling mechanism is provided that provides torque that counteracts torque fluctuations caused by the inconstant speed mechanism,
The torque leveling mechanism is provided in a power transmission path that transmits power to the planting arm shaft, and a crank that partially forms a crank shape that rotates at twice the number of rotations of the planting arm shaft. And a spring attached to the crank portion, the torque is applied by the spring, and the spring is a separate member from the spring and can be locked to the outer periphery of the crank portion Rice transplanter characterized by being attached via a hook. The hook has a curved surface portion that curves according to the outer peripheral shape of the crank portion, and a locking portion that extends from the curved surface portion toward the spring side and through which the end portion of the spring can be inserted. A plurality of planar portions formed in order,
2. The rice transplanter according to claim 1, wherein the spring is fixed to the hook by being sequentially inserted into a plurality of engaging portions provided on a flat portion of the hook. A rice transplanter that transmits power to a planting arm shaft that supports a rotary case via an inconstant speed mechanism,
The planting arm shaft is driven through a chain in a planting chain case,
A torque leveling mechanism is provided in the planted chain case to apply torque that counteracts torque fluctuations caused by the inconstant speed mechanism, and the torque leveling mechanism changes the tension of the chain in the planted chain case. A rice transplanter characterized by changing the chain driving force.

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