JP2018038371A - Paddy field machine power transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a transmission by setting an engagement allowance at an engagement point between a gear pair of each gear pair and a shift key by a plurality of gear pairs to a size corresponding to a transmission torque of each gear pair. .. SOLUTION: A plurality of gear pairs arranged in a constantly meshed state and a speed change operating body 70 for selecting any one of the gear pairs are provided, and the speed change operating body 70 constitutes a gear pair. The transmission key portion 71 that can be selectively engaged and disengaged with any one of the transmission gears to be engaged is provided, and the engagement allowance of the transmission key portion 71 with the transmission gear to be engaged is a plurality. Among the gear pairs of the above, the gear pair in which the inter-strain pitch or the seeding pitch is set short is selected so as to be large. [Selection diagram] FIG. 7

Description

  TECHNICAL FIELD The present invention relates to a transmission device for a paddy field work machine provided with a work device such as a seedling planting device for planting seedlings on the ground or a direct sowing device for seeding seeds on the ground on a traveling machine body that can travel and move in a field. .

In paddy field work machines equipped with planting system working devices such as seedling planting devices or direct seeding devices, the power of the engine mounted on the traveling machine is supplied to the seedling planting device or direct seeding device separately from the traveling drive system. It has a power take-out structure. As a paddy field machine of such a structure, there exists a thing of the structure as described in following [1], for example.
[1] A traveling sub-transmission unit of the traveling drive system and first and second inter-strain transmission units for the seedling planting device are housed inside the mission case. The power shifted by the traveling sub-transmission unit is output to the front wheels and the rear wheels via the output shaft and the transmission chain, and the power shifted by the first and second inter-strain transmission unit is seeded through the power take-off shaft. Output to the device. A plurality of gear pairs are used in the first and second inter-gear transmission units, and a target gear pair is selected by a transmission key (clutch body in the patent document) provided in each transmission unit, thereby providing a multi-stage. (See Patent Document 1).

JP 2008-289399 A (see paragraph numbers “0032”, “0036”, “0038”, “0050”, FIG. 3, FIG. 4, FIG. 6)

In the paddy field machine described in the above-mentioned Patent Document 1, the structures of the engagement parts in the respective gear pairs are configured to have almost the same specifications at the engagement positions of the gear pairs of the respective speed stages and the shift keys. Yes. Therefore, the engagement of the speed change key with each gear pair can obtain the same engagement state when any of the plurality of gear pairs is selected as an engagement target.
However, each gear pair, which is a gear for shifting, has a structure in which the gear diameter is variously set according to the gear ratio, and the transmission torque is different for each gear. For this reason, the required strength differs depending on the required torque between the gear pair set so that the transmission torque can be small and the gear pair set with a large transmission torque.
However, in the structure described in the above-mentioned Patent Document 1, the gears set so as to transmit the maximum torque are set so that the engagement margins of all the gear pairs with respect to the shift key are the same. If the engagement allowances of all the gear pairs and the shift keys are designed to be large in accordance with the pairs, the following problems may occur. In other words, the gear pair of the gear stage with a small assumed transmission torque has a structure in which the engagement with the gear shift key is excessively larger than necessary.
Therefore, when the engagement margin in the transmission gear on the small diameter side of the gear pair is increased, the transmission gear itself tends to increase in diameter in order to secure the engagement margin. And if the transmission gear diameter on the small diameter side increases, the transmission gear diameter on the large diameter side that meshes with it will inevitably increase, and there is a risk that the entire gear pair will become large, and there is room for improvement in this regard. .

  The present invention reduces the size of the transmission device by setting the engagement allowance at the engagement position between the gear pair of each shift stage and the shift key by a plurality of gear pairs according to the transmission torque for each gear pair. It is intended.

  The power transmission device of the paddy field working machine according to the present invention is characterized in that a planting system transmission mechanism that shifts engine power and transmits the engine power to a seedling planting device or a seeding device is incorporated in the planting work case unit, and the planting system transmission mechanism Selects a plurality of gear pairs that are always meshed between an input transmission shaft on the upper transmission side and an output transmission shaft on the lower transmission side, and one of the gear pairs. A shift operation body that enables power transmission, and the shift operation body can be selectively engaged / disengaged with any one of the transmission gears constituting the gear pair as an engagement target. An engagement allowance of the shift key portion with respect to the transmission gear to be engaged is shortened between the plurality of gear pairs by shortening the inter-plant pitch by the seedling planting device or the seeding pitch by the seeding device. The more the selected gear pair is selected Is that is configured to be hear.

According to the present invention, among the plurality of gear pairs, as the gear pair in which the inter-plant pitch by the seedling planting device or the sowing pitch by the sowing device is set shorter, the shift key portion with respect to the transmission gear to be engaged is selected. The engagement margin is set to be large.
In other words, considering that a gear pair in which the inter-pitch pitch by the seedling planting device or the sowing pitch by the sowing device is set to be shorter requires a larger transmission torque, The engagement allowance with the speed change key is set larger than the engagement allowance between the gear pair and the speed change key at the part where the inter-strain pitch or the seeding pitch is long. As a result, the engagement margin between the gear pair of each shift stage and the shift key is set in accordance with the transmission torque of each gear pair, and the waste portion of the engagement margin in the gear pair in the portion where the inter-strain pitch or the seeding pitch is long. By omitting, it is possible to reduce the diameter as much as possible, and the overall structure can be made compact.

  In the present invention, between the transmission gears arranged at positions adjacent to each other in the axial direction of the input transmission shaft or the output transmission shaft, in the axial direction of the input transmission shaft or the output transmission shaft. A plurality of collars for setting the interval of the transmission gear, and the interval between the collars is such that the portion where the gear pair in which the inter-strain pitch by the seedling planting device or the sowing pitch by the seeding device is set short is present is the transmission gear. It is preferable that the interval is set at a wide interval so that the amount of engagement of the shift key portion with respect to is increased.

According to the present invention, by using the collar for setting the interval between the transmission gears, the inter-strain pitch by the seedling planting device or the sowing pitch by the sowing device is changed by changing the interval between the colors wide or narrow. be able to.
And, by changing the distance between the collars, the amount of engagement of the speed change key part that enters between the collars with the transmission gear in the gear pair also changes, so it has a simple structure that only changes the distance between the collars. It is possible to obtain a structure capable of changing the engagement amount of the speed change key portion with respect to the transmission gear.

  In the present invention, the distance between the transmission gears in the axial direction of the input-side transmission shaft or the output-side transmission shaft is larger than the distance between the transmission gears existing at a location where the distance between the collars is widened. It is preferable that the distance between the transmission gears existing at the position where the distance between the collars is narrowed is narrowed.

According to the present invention, a plurality of gear pairs are arranged along the axial direction of the input side transmission shaft or the output side transmission shaft. And in the position which adjoins in an axial direction, as a space | interval of the tooth part of the transmission gear which comprises a gear pair, it is color | collars rather than the space | interval of the gear part of the transmission gear which exists in the location which made the space | interval of the collars wide. The space | interval of the tooth | gear part of the transmission gear which exists in the location which narrowed the space | interval of is narrowed.
As a result, the distance between the teeth of the transmission gear in the region where the transmission torque is small is reduced along with the distance between the collars, and the planting speed change mechanism is further downsized and disposed in the planting work case. Easy to configure.

  In the present invention, the speed change operation body includes the speed change key portion and the transmission gear to be engaged by sliding the speed change key portion in the axial direction of the input side transmission shaft or the output side transmission shaft. A slide operation part that selects and operates an engagement position with respect to the transmission key part, and the transmission gear portion intersects a slide operation direction by the slide operation part, with a connection point to the slide operation part as a swing fulcrum. It is preferable that it is configured to be swingable in the engagement direction.

  With this configuration, the slide operation unit that selects and operates the engagement position with respect to the transmission gear as the speed change operation body, and the slide operation direction by the slide operation unit intersects with the connection point to the slide operation unit as the swing fulcrum. By using the speed change key configured to swing in the direction of engagement with the transmission gear, the engagement depth by the speed change key can be appropriately set for each gear pair. The support portion of the slide operation portion in the transmission case equipped with this speed change operation body does not need to correspond to the one that performs a complicated swing operation of the slide operation portion, and can be sealed for a simple slide operation. What is necessary is just to provide a structure. Therefore, it is easy to adopt a relatively simple structure as the seal structure.

  In the present invention, the speed change operation body includes an elastic biasing mechanism that presses and biases the speed change key portion toward the transmission gear to be engaged. The gear pair that is set at a position farther from the swinging fulcrum than the gear pair, and the strain pitch by the seedling planting device or the seeding pitch by the seeding device is set shorter, is pressed by the elastic biasing mechanism. It is preferable to be located away from the urging location toward the swing fulcrum side.

With this configuration, an elastic urging mechanism that presses and urges the shift key portion toward the transmission gear to be engaged is provided, so that the engagement of the shift key with respect to the gear pair is associated with the sliding operation of the shift operation body. The depth can be adjusted automatically.
The pressing biasing position by the elastic biasing mechanism is set at a position farther from the swing fulcrum than the plurality of gear pairs, and the gear pitch between the strains by the seedling planting device or the seeding pitch by the seeding device is set short. Since the pair is located closer to the swinging fulcrum side from the pressing biasing position by the elastic biasing mechanism, the gear pair in which the inter-strain pitch or the seeding pitch is set shorter by the action of the insulator, the elastic biasing mechanism The pressing and urging action by works strongly.
Therefore, even when a large torque is applied to the engagement point between the gear pair and the speed change key, the possibility that the speed change key is easily detached from the engagement point with the gear pair is reduced.

It is a left view of a riding type rice transplanter. It is a diagram which shows a power transmission system. It is an expanded sectional view of the main case part in a mission case. It is explanatory drawing which shows the meshing part of the shift member and lower gear in an auxiliary transmission mechanism. It is a perspective view which shows the connection state of the stock case part and branch case part with respect to a main case part. It is sectional drawing in the up-down direction of the case part between stocks in a mission case. It is an expanded sectional view in the up-and-down direction of the planting system speed change mechanism in the case between stocks. It is a top view which shows the operation part of a planting type transmission mechanism. It is a top view which shows the operating tool of a planting clutch. It is a disassembled perspective view which shows the operating tool of a planting clutch. It is sectional drawing in the horizontal direction of the branch case part in a mission case. It is explanatory drawing which shows the pattern display part in the lever guide part for stock change. It is explanatory drawing which shows the pattern display part of the lever guide part in another embodiment.

Hereinafter, an example of an embodiment of the present invention will be described based on the drawings.
In the description of the present embodiment, the front-rear direction and the left-right direction are described as follows unless otherwise specified. That is, the forward traveling direction (see arrow F in FIGS. 1 and 2) during traveling of the traveling machine 1 such as a riding rice transplanter to which the present invention is applied is “front”, and the traveling direction toward the backward side (FIG. 1). , 2) (see arrow B in FIG. 2) is “rear”, the direction corresponding to the right side with reference to the forward posture in the front-rear direction (see arrow R in FIGS. 2 and 3) is “right”, and similarly the direction corresponding to the left side. (See arrow L in FIGS. 2 and 3) is “left”.

〔overall structure〕
Fig. 1 shows a riding type rice planting as an example of a paddy field working machine equipped with a working device (planting work device) such as a seedling planting device for planting seedlings on the ground or a direct sowing device for sowing seed pods on the ground. The left side of the machine is shown.
This riding type rice transplanter includes a pair of left and right steering operations and driveable front wheels 11F, and a pair of left and right driveable rear wheels 11R as a travel drive device below the body frame 10, and is mounted on the body frame 10. The self-propelled traveling machine body 1 is provided in which the front wheels 11F and the rear wheels 11R are driven by receiving power from the engine E.

The traveling machine body 1 is provided with a driving unit 13 in which an engine E is installed on the driving unit floor 14 at the front of the machine body. On the driving unit floor 14 at the center in the front-rear direction of the traveling body 1 on the rear side of the driving unit 13, a boarding driving unit having a steering handle 15 and a driving seat 12 for steering the front wheels 11F is provided.
A fertilizer application device 9 (corresponding to a granular material supply device) is mounted on the rear portion of the driver seat 12. The fertilizer application device 9 feeds the fertilizer stored in the fertilizer tank 90 by a predetermined amount from a feeding device (not shown), sends the fertilizer to the grooving device 91 equipped in the seedling planting device 2 through a supply path (not shown), and supplies it to the field. Is configured to do. A seedling planting device 2 is supported on the rear side of the traveling machine body 1 through a link mechanism 25 having a hydraulic cylinder 26 for raising and lowering so as to be raised and lowered.
The riding type rice transplanter configured in this way performs planting work of seedlings such as rice on the field by the seedling planting device 2.

In the front part of the traveling machine body 1, preliminary seedling placing stands 17 are arranged on both the left and right sides of the prime mover 13 with a space in the left-right direction so as to be movable back and forth. The seedling planting device 2 is supported at the rear part of the traveling machine body 1 through a link mechanism 25 having a hydraulic cylinder 26 for raising and lowering so as to be raised and lowered.
The riding type rice transplanter configured in this way performs planting work of seedlings such as rice on the field by the seedling planting device 2.

  The seedling planting device 2 is configured in a four-row planting type, and includes a transmission case 21, a planting case 22 that is rotatably supported on the right and left lateral sides of the rear portion of the transmission case 21, and a planting case 22 includes a pair of planting arms 23 (planting claw drive mechanism) provided at both ends of the plant 22, a grounding float 24, and a seedling platform 20 on which a seedling is placed. As the seedling platform 20 is driven to reciprocate laterally to the left and right, the planting case 22 is rotationally driven so that the planting arms 23 alternately take out seedlings from the lower part of the seedling platform 20 and plant them on the rice field. It is configured.

A transmission case M that pivotally supports a front wheel 11F is connected and fixed to the front part of the body frame 10 in the traveling body 1, and an axle case 19 equipped with rear wheels 11R on the left and right is provided at the rear part of the body frame 10. It is supported. A front frame 10F extends forward from the mission case M, and an engine E is mounted sideways on the front frame 10F.
As shown in FIGS. 2 and 3, the left and right sides of the transmission case M are provided with axle cases 16 extending left and right and left and right front wheels 11 </ b> F and 11 </ b> F.
The axle case 19 of the rear wheel 11R is elastically supported below the pair of left and right front and rear frames 10A and 10A so as to be movable up and down separately through the suspension spring 18 so as to be able to perform a left and right rolling operation. .

[Power transmission system]
A power transmission structure in the transmission case M to which the power of the engine E is transmitted will be described.
The power of the engine E input to the mission case M includes a traveling drive system for driving the front wheels 11F, the rear wheels 11R and the like in the mission case M, and the seedling planting device 2 as a planting system working device or The output is branched and output to a working device drive system for driving a seeding device (not shown) and a fertilization drive system for driving the fertilizer application 9.

The transmission case M includes a main case portion 3 in which a sub-transmission mechanism 3A and the like of a traveling drive system is installed, and a stock case portion 4 (corresponding to a planting work case portion) disposed on the rear side of the main case portion 3. And a branch case portion 5.
The inter-case case unit 4 includes an inter-strain transmission mechanism 7 (corresponding to a planting system transmission mechanism) that shifts and transmits the power output from the main case unit 3 to the seedling planting device 2, and the branch case unit 5 includes A branch transmission mechanism 5 </ b> A for branching transmission of power output from the main case part 3 to the fertilizer 9 is provided.

  The power of the engine E is transmitted to the pump shaft 60a of the hydrostatic continuously variable transmission 6 mounted on the outer wall of the main case 3 in the transmission case M, and from the motor shaft 61a of the hydrostatic continuously variable transmission 6. It is input to the inside of the case body 30 in the main case section 3. That is, the hydrostatic continuously variable transmission 6 is used as a continuously variable main transmission, and the power output from the main transmission is further shifted in the transmission case M.

[Travel drive system]
First, the transmission structure of the traveling drive system will be described.
As shown in FIG. 2, the power of the engine E is transmitted to a pump shaft 60 a that is a transmission input shaft of the hydrostatic continuously variable transmission 6 via a belt transmission mechanism 62, and the hydraulic pump 60 is rotationally driven. .
The motor shaft 61a, which is the speed change output shaft of the hydrostatic continuously variable transmission 6, is spline-fitted to the first speed change shaft 31 (corresponding to the upper side speed change shaft) in the case body 30 of the main case portion 3. The first transmission shaft 31 is driven to rotate as the motor 61 rotates.

As shown in FIG. 3, the first transmission shaft 31 is equipped with a traveling drive system upper-side low-speed gear 31a and upper-side high-speed gear 31b so as to rotate together, and the transmission transmission of the work device drive system is reduced. The output gear 31c is attached so as to rotate integrally.
The end of the first transmission shaft 31 opposite to the side connected to the motor shaft 61 a includes a shaft portion 33 a that penetrates the side wall 30 b of the case body 30 and protrudes to the outside of the case body 30. It is inserted into the cylindrical boss portion 33b of the extension shaft 33 and is pivotally supported so as to be relatively rotatable. The extension shaft 33 is provided with a planting transmission gear 33c on the outer peripheral portion of the cylindrical boss portion 33b. Has been.
The output gear 31c for reduction transmission and the planting transmission gear 33c are engaged with a relay gear 32f that is freely loosely fitted to a second transmission shaft 32 described later.

A second transmission shaft 32 (corresponding to a lower transmission shaft) having an axis parallel to the first transmission shaft 31 is pivotally supported by the case body 30. The second transmission shaft 32 includes a lower-side low-speed gear 32a (corresponding to the lower-side gear) that meshes with the upper-side low-speed gear 31a, and a lower-side high-speed gear 32b (which corresponds to the lower-side gear) that meshes with the upper-side high-speed gear 31b. Is supported on the second speed change shaft 32 so as to be relatively rotatable.
The gear pair of the upper side low speed gear 31a and the lower side low speed gear 32a, the gear pair of the upper side high speed gear 31b and the lower side high speed gear 32b, and the second transmission shaft 32 between these gear pairs. The auxiliary transmission mechanism 3A is configured by including a shift member 34 pivotally supported on the auxiliary transmission mechanism 34.
Of the gear pairs, the combination of the upper-side low-speed gear 31a and the lower-side low-speed gear 32a is a low-speed gear pair suitable for work traveling, and the combination of the upper-side high-speed gear 31b and the lower-side high-speed gear 32b is on the road. High-speed gear pair suitable for running.

The shift member 34 is spline-fitted to the second transmission shaft 32 and is supported so as to be able to rotate integrally with the second transmission shaft 32 and to be slidable in the axial direction of the second transmission shaft 32. On both the left and right side surfaces of the shift member 34 facing the left and right gear pairs, there are a lower side low speed gear 32a and a lower side high speed gear 32b, which are located on the lower side in the power transmission direction of each gear pair. The meshing tooth portions 34a and 34b projecting in the left and right directions are provided.
Further, meshing recesses 32c that selectively mesh with the meshing teeth 34a and 34b of the shift member 34 in the lower-side low-speed gear 32a and the lower-side high-speed gear 32b at positions facing the shift member 34, respectively. , 32d are formed.

Of the meshing teeth 34 a and 34 b of the shift member 34, the meshing tooth 34 a on the side facing the lower-side low-speed gear 32 a having a large diameter is near the outer periphery of the shift member 34 and from the outer peripheral surface of the second transmission shaft 32. It is formed at a remote location. The meshing tooth portion 34b on the side facing the lower-side high speed gear 32b having a smaller diameter on the opposite side is formed near the inner peripheral edge of the shift member 34 and close to the outer peripheral surface of the second transmission shaft 32.
Of the meshing recesses 32c and 32d, the meshing recess 32c formed in the lower-side low-speed gear 32a has a shape that can mesh with the meshing tooth portion 34a on the shift member 34 side at a position opposite to the meshing recess 32c. It is formed at a location away from the outer peripheral surface of 32. Further, the meshing recess 32d formed in the lower-side high-speed gear 32b has a shape capable of meshing with the meshing tooth portion 34b on the shift member 34 side at a position opposite to the meshing recess 32d, and is close to the outer peripheral surface of the second transmission shaft 32. Is formed.

  As shown in FIG. 4, the meshing recess 32 d formed in the lower-side high speed gear 32 b is formed in a shape communicating with the shaft support hole 32 e of the lower-side high speed gear 32 b that is externally fitted to the second transmission shaft 32. Thus, the meshing recess 32d formed in the lower-side high speed gear 32b is formed close to the outer peripheral surface of the second transmission shaft 32 to the limit.

The shift member 34 can be operated from the outside of the case body 30 by using an operation plate 34c that supports the shift member 34 in a state of being held in, and an operation rod 34d fixed integrally with the operation plate 34c. It is configured.
The position where the operating rod 34d is pushed most into the case body 30 is the position where the shift member 34 has selected a low-speed gear pair suitable for work traveling, and the operating rod 34d is pulled most outward from the case body 30. The position is a position where the shift member 34 has selected a high-speed gear pair suitable for traveling on the road. A state where the shift member 34 exists at an intermediate position where no gear pair is selected is the neutral position.

The power transmitted to the second transmission shaft 32 via the shift member 34 is transmitted to the front wheel output gear 35b via the interlocking gear 35a fixed to the second transmission shaft 32. The front wheel output gear 35b is spline-fitted to the outer peripheral portion on the right end side of the cylindrical member 35c that is fitted on the front wheel drive shaft 63 so as to be relatively rotatable. The left end side of the cylindrical member 35c is connected to the differential case 66 so as to be integrally rotatable through a boss portion of a rear wheel output bevel gear 35d that is spline-fitted to the outer peripheral portion.
Therefore, when the front wheel output gear 35b is driven, the rear wheel output bevel gear 35d and the differential case 66 are rotationally driven via the cylindrical member 35c. As a result, the left and right front wheel drive shafts 63 are rotationally driven with the rotation of the differential case 66, and the rear wheel input bevel gear 64a and the rear wheel output shaft 64 (which are meshed with the rear wheel output bevel gear 35d) are rotated. (Corresponding to the traveling transmission shaft) is driven to rotate.

A diff-locking claw portion 67a is provided at the right end of the boss portion of the front wheel output gear 35b. A differential lock sliding claw portion 67b that can be engaged with and disengaged from the differential lock claw portion 67a is also formed at the left end portion of the sliding cylinder 67 that is externally fitted to the front wheel drive shaft 63. The differential lock sliding claw portion 67 b is engaged and disengaged by a rotation operation of a differential lock operation pin 68 provided through the case body 30. That is, the sliding cylinder 67 moves along the axial direction of the front wheel drive shaft 63 by the rotation operation of the differential lock operation pin 68, and engages / disengages with respect to the differential lock claw portion 67a of the front wheel output gear 35b.
In the differential lock state in which the differential lock sliding claw portion 67b is engaged with the differential lock claw portion 67a, the differential by the differential device 65 is locked.

[Working equipment drive system]
A working device drive system that transmits power to the seedling planting device 2 of the planting work device will be described separately from the traveling drive system described above.
The power to the seedling planting device 2 is transmitted between the stock case case section via a stock transmission mechanism 7 and a planting clutch 8 (corresponding to a working clutch) in the stock case section 4 attached to the rear of the main case section 3. It is taken out from the output transmission shaft body 42 extended rearward from 4 and transmitted to the rear seedling planting device 2.

  As shown in FIGS. 5 and 6, the inter-case case portion 4 includes an inter-case case main body 40 configured separately from the case main body 30 of the main case portion 3. The inter-case case main body 40 is integrally connected and fixed to the main case portion 3 via a connecting bolt or the like (not shown). The inter-case case part 4 and the main case part 3 are connected in a state where the internal spaces communicate with each other in a sealed state in which the openings 40a and 30a formed at the connecting portions are joined together. ing.

Power transmission from the main case part 3 into the inter-case case part 4 includes a work system transmission shaft 37 provided over the left and right side walls 30b, 30b of the case body 30, a bevel gear 37a fixed to the work system transmission shaft 37, and its bevel gear. This is done via an output bevel gear 38 meshing with 37a.
The work system transmission shaft 37 is provided with a second external gear 36 b provided on the shaft portion of the work system transmission shaft 37 projecting outside the case body 30 on the shaft portion of the extension shaft 33 projecting outside the case body 30. The first external gear 36a is engaged with the first external gear 36a, thereby transmitting power.

In the inter-case case portion 4, as shown in FIG. 6, a work drive shaft 41 (corresponding to a speed change operation shaft) that is long in the front-rear direction is disposed across the front and rear of the inter-case case portion 4.
The work drive shaft 41 is externally fitted to the output transmission shaft body 42 to which the transmission shaft 27 to the rear seedling planting device 2 is coupled and the front end side portion of the output transmission shaft body 42 so as to be relatively rotatable, It has a partial double-shaft structure with a cylindrical shaft body 43 to which power on the upper side in the transmission direction is transmitted.

The front end portion of the cylindrical shaft body 43 located on the transmission upper side is disposed in a state of entering the inside of the case main body 30 of the main case portion 3. A spline portion is formed in a portion of the cylindrical shaft body 43 located closest to the transmission direction, and the spline portion is a spline on the inner peripheral side of the cylindrical boss of the output bevel gear 38 located in the main case portion 3. Inserted in the part.
The output bevel gear 38 is supported on the outer peripheral side of the boss part by a ball bearing 38 a provided on the case body 30 side of the main case part 3, and thereby the cylindrical shaft body 43 inserted on the inner peripheral side is also supported.
Further, the ball bearing 38a provided on the case body 30 side is supported by a portion of the cylindrical shaft body 43 having a slightly larger diameter on the rear side than the portion inserted into the output bevel gear 38. Has been. Furthermore, a larger-diameter portion of the cylindrical shaft body 43 is in contact with the rear end side of the inner race in the ball bearing 38a. Thereby, the position restriction | limiting to the front side of the cylindrical shaft body 43 is performed.

  The cylindrical shaft body 43 is formed with a small-diameter hole 43b communicating with the internal space of the main case portion 3 in front of the large-diameter hole 43a into which the output transmission shaft body 42 is inserted. The small-diameter hole 43b and the large-diameter hole 43a of the cylindrical shaft body 43 serve as an inner peripheral passage that communicates the internal space of the main case portion 3 and the internal space of the inter-case case portion 4.

An intermediate cylindrical body 44 and a rear cylindrical body 45 are fitted on the outer peripheral portion of the output transmission shaft body 42 on the rear side of the portion where the cylindrical shaft body 43 exists so as to be relatively rotatable.
A torque limiter 46 is provided between the rear end portion of the intermediate cylindrical body 44 and the front end portion of the rear cylindrical body 45.
A planting clutch 8 is provided between the rear end portion of the rear cylindrical body 45 and the output transmission shaft body 42 on the rear side of the rear cylindrical body 45.
Thus, the intermediate cylindrical body 44 and the rear cylindrical body 45 are externally fitted on the outer peripheral portion of the output transmission shaft body 42 so as to be relatively rotatable, and the output transmission shaft body 42 has a cylindrical shaft. Since it exists in the internal peripheral side channel | path of the body 43, it is easy to perform the lubrication in the stock case part 4 favorably.
That is, the lubricating oil existing in the internal space of the main case part 3 flows through the inner peripheral side of the output bevel gear 38 and the cylindrical shaft body 43 and the intermediate cylinder as shown by the broken arrows in FIG. Rotate on the work drive shaft 41 between the intermediate body 44, between the intermediate cylindrical body 44 and the rear cylindrical body 45, and between the rear cylindrical body 45 and the rear output transmission shaft body 42. Lubrication can be satisfactorily performed while utilizing the centrifugal force accompanying the rotation of the member.

[Inter-shaft transmission mechanism]
The inter-stock transmission mechanism 7 will be described.
The inter-strain transmission mechanism 7 includes a first transmission unit 7A located on the upper transmission side and a second transmission unit 7B located on the lower transmission side. The first transmission unit 7A is configured to perform a two-step shift, and the second transmission unit 7B is configured to perform a shift in three stages of high, medium, and low, and a shift is performed using a total of six shift stages. Has been.

In the first transmission unit 7A, a shift gear 47 provided on the cylindrical shaft body 43 of the work drive shaft 41 and a driven gear 48a fixedly supported by the front end portion of the transmission shaft 48 positioned in parallel with the work drive shaft 41. And are provided.
The cylindrical shaft body 43 has a spline portion 43c formed on the outer peripheral portion, and a shift gear 47 fitted on the spline portion 43c is equipped so as to be integrally rotatable and slidable. The shift gear 47 includes a first tooth portion 47a and a second tooth portion 47b having slightly different number of teeth and having approximate diameters, and either one of the tooth portions 47a and 47b meshes with the driven gear 48a alternatively. As is possible, the position of the cylindrical shaft body 43 can be changed along the axial direction.

  As shown in FIG. 6, the shift range of the shift gear 47 is such that both the first gear portion 47a and the second gear portion 47b are located in the inter-case case portion 4, and the first gear portion 47a portion. All or part of the shift operation position can be switched to a first shift position that protrudes from the inter-case case portion 4 and is located in the internal space of the main case portion 3. The operating range of the inter-stock shift operating member 100 is set so that the shift gear 47 can be moved between the first shift position and the second shift position.

In the shift gear 47, an interval is formed between the first tooth portion 47a and the second tooth portion 47b so that a locking pin 102 of the inter-stock transmission operation member 100 described later can be inserted.
The shift gear 47 includes a boss portion 47c that protrudes forward from the first tooth portion 47a, and a portion corresponding to the boss portion 47c is provided toward the rear side from the second tooth portion 47b. It is not done. That is, the shift gear 47 is provided with the boss portion 47c only on the front end portion side which is one end portion of the end portions in the front-rear direction. The protruding length of the boss portion 47 c is set so as to prevent the shift gear 47 from being assembled in the reverse direction in the front-rear direction with respect to the cylindrical shaft body 43.

That is, when the shift gear 47 is assembled in the front-rear direction with respect to the cylindrical shaft body 43, the boss portion 47c of the shift gear 47 even if the first tooth portion 47a is operated to the engagement side with the driven gear 48a. The first end portion 47a cannot be moved to the position where the driven gear 48a is engaged with the front end portion 44a of the intermediate cylindrical body 44.
Thus, since the protruding length of the boss portion 47c is set, the fact that the boss portion 47c is provided only at one end serves as a means for preventing the shift gear 47 from being assembled in the reverse direction. Yes.

A variable speed shaft 48 (corresponding to an input side transmission shaft) is provided in the inter-case case portion 4 and is positioned in parallel with the work drive shaft 41. A second transmission portion 7B is provided across the transmission shaft 48 and the output transmission shaft body 42 of the work drive shaft 41.
The second transmission unit 7B includes a plurality (three in the figure) of transmission gears 49 (corresponding to transmission gears) supported by the transmission shaft 48 on the lower transmission side of the driven gear 48a and the transmission gears. A plurality of (three in the figure) driven transmission gears 44b (transmission gears) fixed to an intermediate cylindrical body 44 (corresponding to the output-side transmission shaft) fitted in the output transmission shaft body 42 in a state of being normally engaged with the output transmission shaft body 42. The gear pair is provided.
The transmission gear 49 supported by the transmission shaft 48 is provided in a loosely fitted state so as to be rotatable relative to the transmission shaft 48.

Between the plurality of transmission gears 49 and the plurality of driven transmission gears 44b in the normally engaged state, any one of the plurality of transmission gears 49 is operated by a transmission operation body 70 that is slid in the transmission shaft 48. By selecting one, the transmission power is transmitted to the output transmission shaft body 42 side through the gear pair.
That is, with respect to the driven transmission gear 44b meshed with the transmission gear 49 selected by the transmission operation body 70, the rotation of the transmission shaft 48 causes the gear ratio between the transmission gear 49 and the driven transmission gear 44b engaged with each other. It is transmitted as shifting power according to.

The speed change operating body 70 includes a speed change key portion 71 including a locking projection 71 a configured to be engageable with and disengageable from an engagement recess 49 a formed on the inner peripheral side of each speed change gear 49, and the speed change key portion 71. And a slide operation portion 72 for selecting and operating the engagement position with respect to the transmission gear 49 to be engaged.
Further, an elastic biasing mechanism 73 is provided that presses and biases the locking protrusion 71a of the speed change key portion 71 against the engagement recess 49a on the inner peripheral side of the speed change gear 49 to be engaged.

As shown in FIGS. 6 and 7, the speed change key portion 71 and the slide operation portion 72 include a rear end side projecting piece 71 b of the speed change key portion 71 in an outer peripheral groove 72 a formed at the front end portion of the slide operation portion 72. It is connected by entering.
Therefore, as the slide operation unit 72 is pushed and pulled back and forth in the axial direction, the speed change key portion 71 also moves back and forth in the same direction.
The state shown in FIG. 6 has shown the state which pushed the slide operation part 72 into the inside of the inter-case case main body 40 most. In this state, the locking projection 71a of the speed change key portion 71 engages with the engagement recess 49a of the speed change gear 49 on the foremost end side of the plurality of speed change gears 49, and the rotational power of the speed change shaft 48 is transferred to the front end. Is transmitted to the transmission gear 49 on the side.
The state in which the transmission gear 49 on the foremost end side is selected is the low-speed transmission position at which the rotation of the transmission shaft 48 is transmitted to the output transmission shaft body 42 side at the lowest speed in the second transmission unit 7B.

The foremost transmission gear 49 located at the low-speed transmission position is constituted by an eccentric gear, and meshes with the foremost driven transmission gear 44b on the intermediate cylindrical body 44 side, which is also constituted by an eccentric gear.
In the transmission state at the low-speed transmission position, the driving speed of the planting arm 23 in the seedling planting device 2 with respect to the traveling speed is the slowest, and the inter-strain pitch is the longest in the second transmission unit 7B. At this time, the drive torque of the transmission gear 49 by the transmission shaft 48 can be minimized.
Further, in the transmission state at this low-speed transmission position, the rotation of the transmission shaft 48 is transmitted to the intermediate cylindrical body 44 side in the transmission state at an unequal speed. This is because the driving speed of the planting arm 23 is the slowest, so that it is possible to avoid as much as possible that the nail during planting is dragged in the mud on the paddy surface. That is, in the driving rotation trajectory of the planting arm 23, the driving speed in a range where the claw is present in the mud is partially increased so that the claw can be quickly removed from the mud.

The state shown in FIG. 7 shows a state in which the slide operation unit 72 is most pulled out to the outside of the inter-case case main body 40. In this state, the locking projection 71a of the speed change key portion 71 is engaged with the engagement recess 49a of the speed change gear 49 on the rear end side of the plurality of speed change gears 49, and the rotational power of the speed change shaft 48 is supplied to the rear end. Is transmitted to the transmission gear 49 on the side.
The state in which the rearmost transmission gear 49 is selected is the high-speed transmission position at which the rotation of the transmission shaft 48 is transmitted to the output transmission shaft body 42 side at the highest speed in the second transmission unit 7B. In the transmission state at this high-speed transmission position, the driving speed of the planting arm 23 in the seedling planting device 2 with respect to the traveling speed is relatively high, and the inter-strain pitch is the shortest in the second transmission unit 7B. At this time, the drive torque of the transmission gear 49 by the transmission shaft 48 becomes the largest.

Although not shown, an intermediate position between the state in which the slide operation unit 72 is most pushed into the inter-case case body 40 and the state in which the slide operation unit 72 is pulled out to the outermost side is a medium speed transmission position.
At this intermediate speed transmission position, the locking protrusion 71 a of the speed change key portion 71 engages with an engagement recess 49 a of the speed change gear 49 that exists at an intermediate position among the plurality of speed change gears 49. Rotational power is transmitted to the transmission gear 49 at the intermediate position. In the transmission state at the medium speed transmission position, the driving speed of the planting arm 23 in the seedling planting device 2 with respect to the traveling speed is an intermediate speed, and the inter-pitch pitch is also an intermediate length. At this time, the driving torque of the transmission gear 49 by the transmission shaft 48 also becomes an intermediate magnitude.

  The elastic biasing mechanism 73 presses and biases the steel balls 73b biased by the coil spring 73a against the recessed portions 71c formed at a plurality of positions in the longitudinal direction of the speed change key portion 71. When the steel ball 73b is pressed and urged against the recessed portion 71c of the speed change key portion 71, a locking projection 71a formed to protrude on the opposite side to the recessed portion 71c is formed in the transmission gear 49 to be engaged. It is pressed and urged against the engagement recess 49a on the circumferential side. The elastic biasing mechanism 73 is configured by including the coil spring 73a, the steel ball 73b, and the recessed portion 71c.

The shift key portion 71 is an elastic urging mechanism 73 with the engagement portion between the outer peripheral groove 72a and the rear end-side protruding piece 71b as a swing fulcrum, which is a connection portion between the shift key portion 71 and the slide operation unit 72. Is configured to be capable of swinging toward the engaging recess 49a on the inner peripheral side of the transmission gear 49 in a direction that intersects with the pressing and urging direction of FIG.
Then, the pressing biasing portion by the elastic biasing mechanism 73 is provided at a position farther from the swing fulcrum than the plurality of gear pairs in the second transmission unit 7B. Therefore, the pressing and urging action by the elastic urging mechanism 73 is stronger in the gear pair in which the stock pitch is set shorter by the action of the lever.

Of the transmission gear 49 in the second transmission unit 7B, the high-speed gear on the rear end side and the medium-speed gear at the intermediate position are sandwiched from both sides by the collar 74, respectively. The foremost low-speed gear is provided between the collar 74 and a part of the transmission shaft 48.
As shown in FIG. 7, the intervals a1, a2, and a3 between the collars 74 are such that the shift key portion 71 is engaged with the transmission gear 49 at locations where there is a gear pair with a short inter-plant pitch set by the seedling planting device 2. Wide intervals are set so that the total amount increases.
That is, the locking protrusion 71a is formed in a tapered mountain shape as shown in FIGS. Therefore, if the distances a1, a2 and a3 between the collars 74 are wide, they engage deeply with the engaging recess 49a of the transmission gear 49, and the engagement margin increases. The engagement allowance for the recess 49a is reduced.

In the speed change gear 49 in the second speed change portion 7B, the front and rear widths of the tooth portions 49b that mesh with the driven speed change gear 44b are all set to the same width, but on the hub surface of each speed change gear 49 in the circumferential direction. The bulging part 49c scattered in several places is formed. The protruding amount of the bulging portion 49 c is different for each transmission gear 49.
That is, as shown in FIG. 7, the foremost low-speed gear has a bulging portion 49c with a small amount of protrusion on the rear hub surface, and the intermediate speed medium-speed gear has a large amount of protrusion on the rear hub surface. A bulging portion 49c is formed. The rearmost high-speed gear is formed with bulging portions 49c and 49c projecting from the front and rear hub surfaces in both the front and rear directions.
Thereby, the width in the front-rear direction including the width of the tooth portion 49b and the bulging portion 49c of the transmission gear 49 is set to a width that matches the intervals a1, a2, and a3 between the collars 74 described above.

  As a result, the distances b1 and b2 between the teeth 49b of the transmission gear 49 are equal to the distance b1 between the teeth 49b and the teeth of the transmission gear 49 that are present at positions where the intervals a1, a2 and a3 between the collars 74 are widened. Rather, the interval b2 between the tooth portions 49b of the speed change gear 49 existing at the locations where the intervals a1, a2, a3 between the collars 74 are narrowed is set to be smaller.

The speed change operation body 70 is slid in the axial direction of the speed change shaft 48 by operating the second speed change lever 75.
As shown in FIGS. 5 and 6, a second speed change lever 75 is connected to the slide operation portion 72 of the speed change operation body 70 at its rear end portion so as to be relatively rotatable. The lower end portion of the second speed change lever 75 is connected to the slide operation portion 72, and an intermediate portion in the vertical direction is supported by a lever support portion 76 provided on the upper portion of the inter-case case main body 40.
Thereby, in the part of the slim of the second speed change lever 75, the center of the slim part at the intermediate position along the vertical direction of the second speed change lever 75 is at the portion that is supported by the lever support 76 so as to be relatively rotatable. The second shift lever 75 is swung around the swing center line y1 indicating the actual swing center.
Therefore, the slide operation portion 72 of the speed change operating body 70 is configured to slide along the axial direction of the speed change shaft 48 by swinging the second speed change lever 75 about the swing center line y1. ing.
The lever support portion 76 supports the intermediate portion of the second shift lever 75 in the vertical direction so as to be relatively rotatable. A pair of upper and lower concave pivot support portions 76a formed in a U shape in plan view is provided so as to allow position movement within a predetermined range. In this way, by allowing the intermediate portion of the second shift lever 75 in the vertical direction to move within a predetermined range in the horizontal direction, the shaft center of the intermediate portion of the second shift lever 75 in the vertical direction The matching swing center line y1 also moves within a predetermined range in the left-right direction.
In other words, by supporting the swing center line y1 in a state in which the swing center line y1 can move within a predetermined range in the left-right direction, the second speed change lever 75 is prevented without hindering the forward / backward movement of the slide operation unit 72 that moves linearly. It is comprised so that rocking | fluctuation operation of can be performed.

The inter-company transmission operation member 100 in the inter-company transmission mechanism 7 is configured as shown in FIGS.
That is, the locking pin 102 that fits between the first tooth portion 47a and the second tooth portion 47b is fixed to the lower end portion of the operation shaft 101 that penetrates the upper wall portion of the inter-case case portion 4, and the upper wall A plate-like operating body 103 is provided at the upper end of the operating shaft 101 located outside the portion.
By rotating the plate-like operation body 103 around the axis of the operation shaft 101, the locking pin 102 existing in the eccentric position is configured to change the position of the shift gear 47 in the axial direction of the work drive shaft 41. Has been. The position of the plate-like operating body 103 around the axis is determined by the ball detent mechanism 104.

Although the description of the intermediate linkage mechanism is omitted in the inter-company transmission operation member 100 for operating the first transmission unit 7A of the inter-company transmission mechanism 7, the plate-like operation body 103 is connected to the first transmission lever 77 shown in FIG. Has been.
The upper end portion of the first speed change lever 77 is provided in a state of being located in the T-shaped guide groove 111 of the lever guide portion 110 provided on the operating portion floor 14 of the traveling machine body 1. The upper end portion of the first speed change lever 77 is located in the left and right side guide groove 111 in the drawing, and is guided in the guide groove 111 and is in one of two positions, the first speed change position and the second speed change position. The position can be changed so that can be selected.
An upper end portion of the second speed change lever 75 for operating the second speed change portion 7B is also located in the guide groove 111 in the front-rear direction along the front-rear direction in the guide groove 111 of the lever guide portion 110, and the guide groove While being guided by 111, the position can be changed so that any one of three positions of a low speed shift position, a medium speed shift position, and a high speed shift position can be selected.

In the lever guide portion 110, pattern display portions 112 on which a numerical value indicating a stock pitch is described are provided on both the left and right sides of the T-shaped guide groove 111.
In the example shown in FIG. 12, there is a character pattern “14” that supports a 14 cm inter-stock pitch in the upper left part of the figure. In order to set the inter-stock pitch of 14 cm, the first speed change lever 77 should be positioned at the left end of the guide groove 111 and the second speed change lever 75 should be positioned to the right of the frontmost “14” character pattern. . In this state, the first speed change lever 77 is operated to the high speed side at the first speed change position and the second speed change lever 75 is also operated to the high speed speed change position. Is set to the densest 14 cm.

From this state, when the first speed change lever 77 is operated toward the right end portion of the guide groove 111 and operated to the front position of the character pattern “16”, the first speed change lever 77 is switched to the second speed change position, and the low speed side. It will be in the state switched to. Therefore, if the position of the second shift lever 75 does not change, the inter-stock pitch is set to 16 cm.
Further, if the position of the second shift lever 75 is positioned to the left of the character pattern “21” from this state, the inter-stock pitch is set to 21 cm, and if it is positioned to the left of the character pattern “28”, the inter-stock pitch is It is set to 28 cm.
When the same operation is performed with the first speed change lever 77 positioned at the left end of the guide groove 111, the position of the second speed change lever 75 is located to the right of the character pattern “18” and the inter-stock pitch is 18 cm. Is set to the right side of the character pattern “24”, the inter-stock pitch is set to 24 cm.

That is, the left and right movements of the first shift lever 77 switch the shift gear 47 between the first shift position and the second shift position, and select the left character pattern group and the right character pattern group of the guide groove 111, The target character pattern can be selected from each character pattern group by the back-and-forth movement of the second speed change lever 75.
Therefore, it is easy to set the inter-stock pitch based on the operation positions of the first shift lever 77 and the second shift lever 75 in a state where there are few erroneous operations visually.
The guide groove 111 of the lever guide part 110 is configured by a through hole formed in the operation part floor 14 of the traveling machine body 1. FIG. 12 is an explanatory diagram in plan view showing the pattern display unit 112 in the lever guide unit 110. The first speed change lever 77 and the second speed change lever 75 in the guide groove 111 are provided so as not to protrude above the upper surface of the driving unit floor 14 and are usually hidden by a mat on the driving unit floor 14. In this state, it can be operated by rolling the mat as necessary.

The power changed by the stock shifting mechanism 7 is transmitted from the intermediate cylindrical body 44 to the torque limiter 46.
The torque limiter 46 includes a disc-shaped receiving plate 46a fixed to the rear end portion of the intermediate cylindrical body 44, a pressing plate 46b that contacts the receiving plate 46a, and the pressing plate 46b toward the receiving plate 46a. And a coil spring 46c that presses and biases the coil spring 46 toward it. Through this torque limiter 46, the shift power from the inter-shaft transmission mechanism 7 is transmitted to the planting clutch 8.

[Planting clutch]
The planting clutch 8 is configured as follows.
Of the work drive shaft 41, the rear end portion of the rear cylindrical body 45 is engaged with the outer peripheral side spline of the rear cylindrical body 45 to rotate integrally with the rear cylindrical body 45. 80 is provided.
On the outer peripheral side of the output transmission shaft body 42 extending rearward from the rear cylindrical body 45, the spline portion 42 a formed on the outer peripheral surface of the output transmission shaft body 42 is engaged and output. A driven-side rotating member 81 is provided that can rotate integrally with the transmission shaft 42 and move in the axial direction of the output transmission shaft 42.
The driven-side rotating member 81 is pressed and urged toward the driving-side rotating member 80 by a pressing spring 82, and the opposing surfaces of the driving-side rotating member 80 and the driven-side rotating member 81 are mutually opposed. Engagement portions 80a and 81a capable of transmitting power in an engaged state are formed.

The pressing spring 82 is provided between a spring receiving portion 81b formed on the surface opposite to the side where the meshing portion 81a of the driven side rotating member 81 is formed and a fixed portion on the inner surface side of the inter-case case portion 4. It has been. As the fixed portion on the inner surface side of the inter-case case portion 4, the inner end portion of the inner race 40c of the ball bearing 40b that supports the output transmission shaft body 42 is used, but it is not always necessary to be at this position.
The shape of the pressing spring 82 is such that the winding diameter at the end of the work drive shaft 41 in contact with the spring receiving portion 81b in the axial direction is larger than the winding diameter at the side contacting the inner end of the inner race 40c. It is formed in the set truncated cone shape.
Of this pressing spring 82, the winding diameter on the side in contact with the inner end of the inner race 40c is configured to be the same as or slightly larger than the outer diameter of the externally fitted output transmission shaft body 42. Therefore, the position of the end portion can be positioned by using the inner end portion of the inner race 40c of the ball bearing 40b that supports the output transmission shaft body 42 without requiring any special positioning means.

As shown in FIG. 6, the driven-side rotating member 81 is operated to the side away from the driving-side rotating member 80 against the biasing force of the pressing spring 82 by a clutch operating member 83 that is in contact with the outer peripheral portion. And an engaging portion 81c with which the clutch operating member 83 is engaged is provided on the outer peripheral portion.
The clutch operation member 83 includes an operation pin 84 that penetrates the upper wall portion of the inter-case case portion 4. The lower end portion of the operation pin 84 abuts on the engagement portion 81 c of the driven side rotation member 81, and the operation pin 84. With the rotation operation, an operation portion 84a for moving the driven side rotation member 81 in the axial direction of the output transmission shaft body 42 is formed.

The clutch operating member 83 is a shaft end portion of the operation pin 84 at a portion exposed to the outside of the inter-case case portion 4 among the operation pins 84 operated around the rotation axis p <b> 1 in a direction intersecting the axis of the work drive shaft 41. Further, an operation plate 85 for rotating the operation pin 84 is attached. An operation guide member 86 that guides the rotation operation of the operation plate 85 about the rotation axis p <b> 1 while supporting a part of the operation plate 85 so as to be sandwiched between the upper and lower sides is provided on the outer side of the inter-case case portion 4. Is provided.
As a result, the position of the operation pin 84 in the direction along the rotation axis p <b> 1 is restricted by the operation plate 85, and the operation range around the rotation axis p <b> 1 is abutted between the operation plate 85 and the operation guide member 86. Regulated by.

The position of the spring receiving portion 81b of the driven-side rotating member 81 with respect to the engaging portion with the engaging portion 81c of the driven-side rotating member 81 at the lower end portion of the operation pin 84 is the radius of the driven-side rotating member 81. And in the axial direction of the work drive shaft 41, the position closer to the facing surface where the meshing portion 81 a is formed than the location where the driven rotation member 81 is engaged with the engagement portion 81 c. Is provided.
As described above, the spring receiving portion 81b is located on the inner side in the radial direction from the engagement portion between the operation pin 84 and the engagement portion 81c of the driven side rotation member 81, and on the side where the engagement portion 81a exists. The shape is greatly recessed so as to be close to each other. Thus, the axial length of the work drive shaft 41 of the pressing spring 82 can be prevented from being restricted by the position of the operation pin 84 in the axial direction of the work drive shaft 41, and the inter-case case portion 4 can be made compact. Can be planned.

[Fertilization drive system]
The fertilizer application drive system that branches and transmits the driving force to the fertilizer application device 9 from the traveling drive system described above is configured as follows.
As shown in FIG. 11, a branch case portion 5, which is configured separately from the main case portion 3, is connected and fixed to the rear side of the main case portion 3 through mounting bolts (not shown). ing.
The main case part 3 and the branch case part 5 communicate with each other in a sealed state in which the openings 30a and 50a formed at the connecting portions are joined to each other.

As shown in FIG. 11, the branch case portion 5 has an input side tubular portion 50 </ b> A that supports the rear wheel output shaft 64 extending rearward from the main case portion 3 and a direction intersecting the rear wheel output shaft 64. An output side tubular portion 50B that is externally fitted to the extended branch transmission shaft 51 and supports the branch transmission shaft 51 is provided. The input-side cylindrical portion 50A and the output-side cylindrical portion 50B are configured as a single body having a common internal space.
A branch output bevel gear 52 that transmits power from the rear wheel output shaft 64 to the branch transmission shaft 51 is provided in the input side tubular portion 50A, and a fertilizer bevel gear 53 (branch input bevel gear 53) that meshes with the branch output bevel gear 52. Is provided in the output-side cylindrical portion 50B.
The branch output bevel gear 52 is provided in the input side cylindrical portion 50 </ b> A closer to the main case portion 3 than the branch transmission shaft 51.

A rear wheel output shaft 64 having a front wheel input bevel gear 64a meshing with the rear wheel output bevel gear 35d at the front end is supported by a ball bearing 39 provided on the case body 30 of the main case 3 on the front end side. The end portion is supported by a ball bearing 54 provided near the rear end portion of the branch case portion 5.
The rear wheel output shaft 64 is provided with a stepped portion 64C (corresponding to a positioning portion) at an intermediate position in the axial direction, and the front portion corresponding to the upper side in the transmission direction is larger in diameter than the stepped portion 64C. In the shaft portion 64A, a rear side corresponding to the lower side in the transmission direction than the stepped portion 64C is formed in the small-diameter shaft portion 64B.
The step portion 64C is formed near the boundary between the main case portion 3 and the branch case portion 5, and a spline portion 64D is formed in a portion near the step portion 64C in the small-diameter shaft portion 64B. The spline portion 64D is branched to the spline portion 64D. The output bevel gear 52 is spline-fitted.

An opening 50 a of the branch case portion 5 formed at a location facing the main case portion 3 has an inner diameter through which the branch output bevel gear 52 supported by the rear wheel output shaft 64 can be inserted.
Therefore, when the rear wheel output shaft 64 is assembled into the branch case portion 5, it can be incorporated into the branch case portion 5 in a state where the branch output bevel gear 52 is previously supported on the rear wheel output shaft 64. Convenience can be achieved.

A branch transmission shaft 51 equipped with a fertilization bevel gear 53 that meshes with a branch output bevel gear 52 supported by the rear wheel output shaft 64 at the input side end is arranged in a posture orthogonal to the rear wheel output shaft 64. ing. And it is comprised so that an input side edge part can be inserted / extracted from the output side opening 50b side formed in the output side cylindrical part 50B of the branch case part 5, and the output side edge part is the output side opening 50b of the output side cylindrical part 50B. It is supported in a state protruding from the outside.
An unillustrated interlocking shaft to the fertilizer application device 9 is connected to the projecting portion of the branch transmission shaft 51 projecting outward from the output side opening 50b.

  Further, the branch transmission shaft 51 is a portion corresponding to the insertion limit position to the output side tubular portion 50 </ b> B, and the input side end abuts against the rear wheel output shaft 64. That is, when the branch transmission shaft 51 is inserted into the output-side tubular portion 50B from the output-side opening 50b until reaching the insertion limit position, the input-side end portion is in such a positional relationship that it abuts against the rear-wheel output shaft 64. The position of the rear wheel output shaft 64 with respect to the side tubular portion 50A is determined.

  The fertilization bevel gear 53 is supported so as to be rotatable relative to the branch transmission shaft 51, and the branch transmission shaft 51 and the fertilization bevel gear 53 can be freely engaged and disengaged via a fertilization clutch 55 (corresponding to a work clutch). It is configured.

The fertilization clutch 55 includes a cylindrical shift member 56 that is spline-fitted to a spline portion formed on the outer peripheral surface of the branch transmission shaft 51. Then, by engaging / disengaging the claw portion 56a formed on the surface of the cylindrical shift member 56 facing the fertilizer bevel gear 53 and the engaging recess 53a on the fertilizer bevel gear 53 side facing the cylindrical shift member 56. The fertilization bevel gear 53 is configured to be switchable between a state where the rotation of the bevel gear 53 is transmitted to the branch transmission shaft 51 and a state where the transmission is cut off.
The cylindrical shift member 56 is pressed and biased toward the fertilizer bevel gear 53 by a coil spring 57, and a clutch operating shaft that operates the cylindrical shift member 56 toward the side away from the fertilizer bevel gear 53 against this pressing bias force. A body 58 is provided so as to penetrate the output-side cylindrical portion 50B.

[Other Embodiment 1]
In said embodiment, although the rice transplanter provided with the plant | casing case part 4 as a planting work case part was shown, it is not restricted to this. For example, when used in a seeder equipped with a direct seeding device, the seeding work case unit becomes a work case unit for changing the seeding interval by the direct seeding device.
Other configurations may be the same as those in the above-described embodiment.

[Second embodiment]
In said embodiment, although the fertilizer application apparatus 9 is used as a granular material supply apparatus, it is not restricted to this.
For example, a medicine such as a herbicide or a pest repellent may be supplied.
Other configurations may be the same as those in the above-described embodiment.

[3 of another embodiment]
In the above-described embodiment, the pattern display portion 112 in the lever guide portion 110 is illustrated as having a structure provided on the left and right sides of the T-shaped guide groove 111, but is not limited to this structure.
For example, as shown in FIG. 13A, it is arranged on the front side and the lateral side of the L-shaped guide groove 111, or as shown in FIG. The thing of appropriate structure, such as these, is employable.
Other configurations may be the same as those in the above-described embodiment.

[4 of another embodiment]
In the above-described embodiment, the speed change operating body 70 of the inter-shaft speed change mechanism 7 is provided on the speed change shaft 48 provided as the shaft corresponding to the input side transmission shaft, and is fixed to the intermediate cylindrical body 44 provided as the output side transmission shaft. Although the structure is illustrated as an example in which power transmission is selectively performed with respect to the driven transmission gear 44b, the structure is not limited to this structure.
For example, a fixed transmission gear is provided on the side of the transmission shaft 48 provided as a shaft corresponding to the force-side transmission shaft, and a transmission gear capable of relative rotation is provided on the intermediate cylindrical body 44 provided as the output-side transmission shaft. You may comprise so that the transmission gear 70 may select the transmission gear which can be relatively rotated by the side of the intermediate cylinder 44. FIG.
Other configurations may be the same as those in the above-described embodiment.

  The present invention is not limited to a riding type rice transplanter for four-row planting, but can be applied to a paddy field working machine employing a small number of three or less, or five or more seedling planting devices and direct seeding devices.

1 traveling machine body 2 seedling planting device (working device)
4 Planting work case 7 Inter-strain transmission mechanism (planting transmission mechanism)
41 Speed change operation shaft 44 Intermediate cylindrical body (output side transmission shaft)
44b Driven gear (transmission gear)
47 Shift gear 48 Shift shaft (input-side transmission shaft)
49 Transmission gear (transmission gear)
49b Tooth
70 Shifting operation body 71 Shifting key part 72 Slide operation part 73 Elastic biasing mechanism 74 Color

Claims (5)

A planting system transmission mechanism that shifts engine power and transmits it to a seedling planting device or a seeding device is incorporated in the planting work case part,
The planting transmission mechanism includes a plurality of gear pairs arranged in a constantly meshed state across an input transmission shaft on the upper transmission side and an output transmission shaft on the lower transmission side, and any one of the gear pairs. A gear shifting operation body that enables transmission of power by selecting two gear pairs,
The speed change operation body includes a speed change key portion that can be selectively engaged / disengaged with one of the transmission gears constituting the gear pair as an engagement target,
An engagement allowance of the shift key portion with respect to the transmission gear to be engaged is, among the plurality of gear pairs, the gear pair in which the inter-plant pitch by the seedling planting device or the sowing pitch by the sowing device is set short. A power transmission device for paddy field machines that is configured to become larger as it is selected. An interval in the axial direction of the input-side transmission shaft or the output-side transmission shaft is set between the transmission gears arranged at positions adjacent to each other in the axial direction of the input-side transmission shaft or the output-side transmission shaft. Multiple colors are deployed,
As for the interval between the collars, the amount of engagement of the shift key portion with the transmission gear increases as the gear pair in which the inter-plant pitch by the seedling planting device or the sowing pitch by the sowing device is set short is present. The transmission device for a paddy field machine according to claim 1, wherein the transmission device is set at such a wide interval.   The distance between the tooth portions of the transmission gear in the axial direction of the input-side transmission shaft or the output-side transmission shaft is greater than the distance between the tooth portions of the transmission gear that is present at a location where the space between the collars is widened. 3. The transmission device for paddy field machine according to claim 2, wherein the interval between the tooth portions of the transmission gear existing at a location where the interval between the collars is narrowed. The speed change operation body slides the speed change key portion and the speed change key portion in the axial direction of the input side transmission shaft or the output side transmission shaft, and sets an engagement position with respect to the transmission gear to be engaged. A slide operation unit for selecting and operating,
The shift key portion is configured to be swingable in an engagement direction with the transmission gear that intersects a slide operation direction by the slide operation portion, with a connection point with respect to the slide operation portion as a swing fulcrum. The transmission device for a paddy field machine according to any one of Items 1 to 3. The shift operation body includes an elastic biasing mechanism that presses and biases the shift key portion toward the transmission gear to be engaged.
The pressing biasing portion by this elastic biasing mechanism is set at a position farther from the swing fulcrum than the plurality of gear pairs,
The gear pair in which the inter-strain pitch by the seedling planting device or the sowing pitch by the sowing device is set shorter, is located closer to the swing fulcrum side from the pressing biasing location by the elastic biasing mechanism. The transmission device for paddy field machine according to claim 4.

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