JP6624836B2 - Paddy working machine - Google Patents

Description

  The present invention relates to a structure of a transmission system to a front wheel and a rear wheel and a transmission system to a working device in a paddy field working machine provided with a seedling planting device and a direct sowing device as a working device.

  In a riding type rice transplanter that is an example of a paddy working machine, as disclosed in Patent Document 1, a traveling transmission that transmits a power to a front wheel and a rear wheel by including a transmission case at a front portion of an airframe, and 2. Description of the Related Art There is a type in which a work transmission that transmits power to a work device is provided inside a transmission case.

JP 2011-251571 A

In the paddy field work machine, a front wheel steering mechanism (a steering shaft operated by a steering wheel, a pinion gear provided on the steering shaft, an operation shaft linked to the front wheel, an operation gear provided on the operation shaft, etc.) is connected to a transmission case. May be provided inside.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a paddy working machine in which a front wheel steering mechanism, a traveling transmission, and a work transmission can be appropriately arranged inside a transmission case.

[I] (Structure)
A first feature of the present invention is that a paddy field working machine is configured as follows.
Inside the transmission case, an input shaft to which power is transmitted, a work transmission shaft, a first traveling transmission shaft, a second traveling transmission shaft, and a front wheel transmission shaft are provided parallel to each other in the left-right direction.
And one side portion in the longitudinal direction of the input shaft, between the one side portion in the longitudinal direction of the first traveling transmission shaft, provided with a first traveling speed change device, said first traveling speed change device Power is transmitted to the front and rear wheels,
A work transmission is provided between the other part of the input shaft in the longitudinal direction and the other part of the work transmission shaft in the longitudinal direction, and the power of the work transmission is provided on the body. Configured to be transmitted to the working device,
A first traveling transmission shaft provided with a second traveling transmission between a second portion of the second traveling transmission shaft in the longitudinal direction and a second portion of the second traveling transmission shaft in the longitudinal direction; Power of a transmission is transmitted to the rear wheels via the second traveling transmission,
A first transmission gear provided on the other side in the longitudinal direction of the second traveling transmission shaft, and a second transmission gear provided on the other side in the longitudinal direction of the front wheel differential mechanism are connected; The front wheel transmission shaft extends from a differential mechanism, and the power of the first traveling transmission is transmitted to the front wheels via the second traveling transmission and the front wheel differential mechanism,
Inside the transmission case, a steering shaft of a front wheel operated by a steering wheel is vertically arranged between the input shaft, the first traveling transmission, the work transmission and a front wall of the transmission case. And, a pinion gear is provided below the steering shaft,
On the bottom of the transmission case on the rear side of the pinion gear, an operation shaft for steering the front wheels is vertically arranged, and an operation gear is provided on an upper portion of the operation shaft,
By engaging the pinion gear and the operation gear, the operation of the steering handle is transmitted to the front wheels via the steering shaft and the operation shaft, and the front wheels are steered.
An operation shaft for performing a traveling operation of the first traveling transmission is connected to a traveling shift shaft via an arm, and the traveling shift shaft is coupled to the first traveling transmission via a traveling fork;
By setting an imaginary line extending the axis of the operation axis upward,
A side view of the input shaft, the first traveling transmission shaft, the work transmission shaft, the second traveling transmission shaft, the front wheel transmission shaft, the first traveling transmission, and the work transmission. Arranged between the virtual line and the rear wall of the mission case ,
The arm and the traveling shift shaft are disposed between the virtual line and a front wall of the transmission case in a side view .

(Action and effect of the invention)
According to the first aspect of the present invention, when an operation shaft for steering the front wheels is provided at the bottom of the transmission case, the input shaft, the traveling transmission shaft and the work transmission shaft, the traveling transmission and the work transmission are viewed from the side. The input shaft, the traveling transmission shaft and the work transmission shaft, the traveling transmission and the work transmission are arranged in a mission by disposing the axis of the operating shaft between the virtual line extending upward and the rear wall of the transmission case. It will be in the state of being located in the rear half inside the case.

  As a result, the steering mechanism (steering shaft) for the front wheels can be appropriately and appropriately arranged in the front half of the transmission case. It is not necessary to make the transmission case unnecessarily large, so that the entire transmission case can be reduced in size and weight.

According to the first feature of the present invention, in the left-right direction inside the transmission case, the traveling transmission is provided on one side and the work transmission is provided on the other side. In this respect, the transmission case can be arranged without difficulty, so that the transmission case does not need to be made unnecessarily large, and the overall size and weight of the transmission case can be reduced.
Also, in the left-right direction inside the transmission case, the first and second traveling transmissions and the working transmission are provided by including a traveling transmission (first traveling transmission) on one side and a work transmission on the other side. However, since the transmission case is arranged without difficulty in the rear half of the interior of the transmission case, the transmission case does not need to be unnecessarily enlarged, and the overall transmission case can be reduced in size and weight. Can be.

[II]
(Constitution)
A second feature of the present invention resides in that the paddy field working machine according to the first feature of the present invention is configured as follows.
The power of the input shaft is configured to be transmitted to the traveling transmission shaft via the traveling transmission, the traveling transmission shaft includes a small-diameter gear, the work transmission shaft includes a large-diameter gear, and the small-diameter By engaging the gear and the large diameter gear,
The power of the input shaft is configured to be transmitted to the traveling transmission shaft, the small-diameter gear, the large-diameter gear, and the work transmission shaft,
A plurality of work gears are fitted to the input shaft so as to be rotatable relative to each other, and the work transmission is provided between the work transmission shaft and the work gear.

(Action and effect of the invention)
In a transmission case, generally, high-speed power is transmitted to the input shaft. Therefore, it is necessary to sufficiently reduce the power of the input shaft before transmitting it to the work transmission.
According to the second feature of the present invention, the power of the input shaft is transmitted to the traveling transmission shaft via the traveling transmission, and is transmitted from the small-diameter gear of the traveling transmission shaft to the large-diameter gear of the work transmission shaft at a sufficiently reduced speed. Therefore, it is easy to set the sufficiently decelerated power to an appropriate speed ratio by the work transmission.

  According to the second feature of the present invention, when configuring the work transmission, the work transmission is configured in a small area between the work transmission shaft and the work gear (input shaft), so that the work transmission is compactly configured. Therefore, the overall size of the transmission system from the input shaft to the working device can be reduced.

[III]
(Constitution)
A third feature of the present invention resides in that the paddy working machine according to the second feature of the present invention is configured as follows.
A reverse work clutch that is operated in a transmission state during forward movement and is operated in a disconnected state during reverse movement is provided between the large-diameter gear and the work transmission shaft.

(Action and effect of the invention)
Since the paddy field working machine cannot perform work while moving backward, it is necessary to stop the working device when moving backward.
According to the third feature of the present invention, the large-diameter gear of the work transmission shaft receiving the power of the small-diameter gear of the traveling transmission shaft is provided with a reverse work clutch, and the reverse operation clutch is operated to be in a disengaged state when the vehicle is moving backward, so that the input is performed. The power can be shut off at a position immediately after the traveling transmission shaft, which is a position close to the shaft, and the working device can be appropriately stopped.

[IV]
(Constitution)
A fourth feature of the present invention resides in that the paddy working machine according to the third feature of the present invention is configured as follows.
The reverse working clutch,
The work transmission shaft is provided with a shift member that can rotate and slide integrally with the shaft,
The transmission member is brought into a transmission state by slidingly operating the shift member to engage the large-diameter gear, and the transmission member is brought into a blocking state by sliding the shift member away from the large-diameter gear.

(Action and effect of the invention)
According to the fourth feature of the present invention, the reverse operation clutch can be configured by the sliding operation of the shift member (occlusion and separation with the large-diameter gear), and the reverse operation clutch can be simply configured.

[VI]
(Constitution)
A sixth feature of the present invention resides in that the paddy field working machine according to the fifth feature of the present invention is configured as follows.
Wherein the first traveling transmission is
A first shift gear integrally rotatably and slidably supported by the input shaft; and a plurality of traveling gears fixed to the first traveling power transmission shaft, wherein the first shift gear is formed of the plurality of traveling gears. It is configured to bite into one,
The second travel transmission includes a second shift gear integrally rotatably and slidably supported on the second travel transmission shaft, and the plurality of travel gears. It is configured to bite into one of them,
Of the plurality of traveling gears, a traveling gear corresponding to the highest speed position of the first and second traveling transmissions is provided at a central portion in the longitudinal direction of the first traveling transmission shaft.

(Action and effect of the invention)
According to a sixth aspect of the present invention, in the first traveling transmission, the first shift gear is engaged with the traveling gear of the first traveling transmission shaft to perform a shift, and in the second traveling transmission, the second shift gear is set to the same second gear. The gear is shifted by engaging with the traveling gear of one traveling transmission shaft, and the traveling gear of the first traveling transmission shaft is a common component of the first and second traveling transmissions.

  According to the sixth aspect of the present invention, since the traveling gear corresponding to the highest speed position of the first and second traveling transmissions is provided at the central portion in the longitudinal direction of the first traveling transmission shaft, The first and second shift gears are engaged with a traveling gear corresponding to the highest speed position of the first traveling transmission, and the second shift gear is engaged with the same traveling gear corresponding to the highest speed position of the first traveling transmission. The highest speed of the two-speed transmission can be obtained.

  In this case, in the input shaft, the first and second traveling transmission shafts, the first and second shift gears and the traveling gear corresponding to the highest speed position of the first and second traveling transmissions are provided in the central portion in the longitudinal direction, Since they are arranged in a line, power flows smoothly from the first traveling transmission to the second traveling transmission at the highest speed positions of the first and second traveling transmissions.

[VII]
(Constitution)
A seventh feature of the present invention resides in that the paddy working machine according to the sixth feature of the present invention is configured as follows.
A first bevel gear is provided on the second traveling transmission shaft toward the second shift gear so that the first traveling transmission shaft is located outside the traveling gear at one end in a longitudinal direction of the first traveling transmission shaft,
A rear wheel transmission shaft for transmitting power to a rear wheel is arranged orthogonal to the second traveling transmission shaft, and a second bevel gear of the rear wheel transmission shaft is meshed with the first bevel gear.

(Action and effect of the invention)
According to a seventh aspect of the present invention, when the second traveling power transmission shaft having the second shift gear is provided with the first bevel gear, the first traveling power transmission shaft is located outside the traveling gear at one end in the longitudinal direction of the first traveling power transmission shaft. By providing the first bevel gear on the second travel transmission shaft so as to be located, the first bevel gear can be comfortably provided on the second travel transmission shaft while avoiding interference with the travel gear and the second shift gear.

  Next, according to the seventh aspect of the present invention, when a rear wheel transmission shaft for transmitting power to the rear wheel is provided and the second bevel gear of the rear wheel transmission shaft is engaged with the first bevel gear, the first bevel gear (first Gears of the bevel gear) are provided on the second traveling transmission shaft toward the second shift gear, so that the second bevel gear is located between the first bevel gear and the second shift gear and faces the traveling gear. It is arranged without difficulty.

[VIII]
(Constitution)
An eighth feature of the present invention resides in that one of the paddy working machines according to the second to seventh features of the present invention is configured as follows.
The work transmission,
A first gear and a second gear are provided on the cylindrical member so as to be rotatable integrally, and the cylindrical member is externally fitted to the work transmission shaft so as to be integrally rotatable and slidable;
Sliding the cylindrical member to one side to engage the first gear with the working gear at the other end of the plurality of working gears, sliding the cylindrical member to the other side, The second gear is engaged with a working gear at one end of the plurality of working gears to perform gear shifting,
The working gear at one end of the plurality of working gears has the smallest diameter among the plurality of working gears, and the working gear at the other end of the plurality of working gears is It is the largest diameter among a plurality of working gears.

(Action and effect of the invention)
According to the eighth feature of the present invention, in the work transmission provided on the other side of the work transmission shaft in the longitudinal direction, and in the cylindrical member provided with the first and second gears, the second gear is the longitudinal member of the work transmission shaft. While the first gear is located at the other end in the longitudinal direction of the work transmission shaft while the first gear is located at the central portion in the direction, the first gear is located at the other longitudinal end of the work transmission shaft. It is in a state close to the bearing at the side end.

According to the eighth feature of the present invention, in the plurality of working gears of the working transmission, the working gear at one end is set to the minimum diameter, and the working gear at the other end is set to the maximum diameter. The second gear that meshes with the working gear at one end has a large diameter, and the first gear that meshes with the working gear at the other end has a small diameter.
Thus, even if the first gear is in a state close to the bearing at the other end in the longitudinal direction of the work transmission shaft, the small diameter of the first gear allows the longitudinal direction between the first gear and the work transmission shaft to be reduced. Interference with the bearing at the other end can be reasonably avoided.

[IX]
(Constitution)
A ninth feature of the present invention resides in that one of the paddy field working machines according to the second to eighth features of the present invention is configured as follows.
On the right or left side of the transmission case, a hydrostatic stepless transmission is provided,
The power of the engine is transmitted to the hydrostatic continuously variable transmission, and the power of the hydrostatic continuously variable transmission is transmitted to the input shaft,
One side in the longitudinal direction of the input shaft, one side in the longitudinal direction of the traveling transmission shaft, one side in the longitudinal direction of the work transmission shaft is the hydrostatic continuously variable transmission side,
The other side of the input shaft in the longitudinal direction, the other side of the traveling transmission shaft in the longitudinal direction, and the other side of the work transmission shaft in the longitudinal direction are opposite to the hydrostatic continuously variable transmission.

(Action and effect of the invention)
According to a ninth feature of the present invention, when the hydrostatic stepless transmission is provided on the right side (left side) of the transmission case, the traveling transmission is provided on the right side (left side) (hydrostatic pressure) inside the transmission case. The work transmission is provided on the left side (right side) (the part on the opposite side of the hydrostatic continuously variable transmission), whereas the work transmission is provided on the part of the type of the continuously variable transmission.
Thereby, the left-right balance of the hydrostatic continuously variable transmission and the transmission case (the traveling transmission and the work transmission) is improved.

It is the whole left side view of a riding type rice transplanter. It is a whole plan view of a riding type rice transplanter. It is the schematic which shows the transmission system to a front wheel and a rear wheel, and the transmission system to a seedling planting apparatus. FIG. 4 is a cross-sectional plan view of a transmission case showing a transmission system to a front wheel and a rear wheel. It is a cross-sectional plan view of the mission case showing a transmission system to the seedling planting device. FIG. 4 is a cross-sectional plan view of the vicinity of first and second work transmissions in a transmission case. FIG. 4 is a cross-sectional plan view of the vicinity of first and second traveling transmissions in a transmission case. FIG. 5 is a cross-sectional plan view of the vicinity of a rear wheel transmission shaft in a transmission case. It is a right vertical section side view of a mission case. It is a right view of a transmission case. It is a rear view of a mission case. It is a perspective view of a mission case. FIG. 3 is a perspective view of a vicinity of a power steering mechanism in a transmission case. It is a cross-sectional plan view of the vicinity of the notch part of a support member and the connection member of a transmission lever. FIG. 4 is a schematic diagram showing the entire shift range of the first and second work transmissions. FIG. 21 is a schematic diagram showing an entire shift range of first and second work transmissions in a seventh alternative embodiment of the present invention.

  In FIGS. 1, 2, 4, 5, 9 to 12, F indicates the "forward direction" of the aircraft, B indicates the "rearward direction" of the aircraft, U indicates the "upward direction" of the aircraft, and D indicates the aircraft. “Downward direction” of FIG. In the state facing the front of the fuselage, R indicates the “right direction” of the fuselage, and L indicates the “left direction” of the fuselage.

[1]
An outline of a riding rice transplanter, which is an example of a paddy field working machine, will be described.

  As shown in FIGS. 1 and 2, a link mechanism 3 that can swing up and down is provided at the rear of the body supported by right and left front wheels 1 and right and left rear wheels 2. At the rear, an eight-row seedling planting device 5 (corresponding to a working device) is supported rotatably around the longitudinal axis, and a hydraulic cylinder 4 that drives the link mechanism 3 up and down is provided. It is configured.

As shown in FIGS. 1 and 2, the seedling planting apparatus 5 includes four transmission cases 6, a pair of rotation cases 7 rotatably supported at the rear of the transmission case 6, and both ends of the rotation case 7. And a pair of planting arms 8, a ground float 9, and a seedling stand 113.
As a result, the rotating case 7 is driven to rotate as the seedling rest 113 is reciprocally traversely driven in the left-right direction, and the planting arm 8 alternately takes out the seedlings from the lower part of the seedling rest 113 to remove the seedlings. Plant.

  As shown in FIG. 1, a transmission case 10 is provided at a front portion of the fuselage. A right (left) front axle case 11 is connected to a rear portion of a right portion 10a (left portion 10b) of the transmission case 10, and a right (left) portion is provided. The right (left) front wheel 1 is steerably supported at the end of the right (left) front axle case 11. A rear axle case 12 is supported at the rear of the fuselage, and a right (left) rear wheel 2 is supported at a right (left) end of the rear axle case 12.

  As shown in FIG. 1, a support frame 13 is connected to a front portion of the transmission case 10 and extends to the front side. An engine 14 is supported by the support frame 13, and a hood 15 that covers the engine 14 is provided. ing.

  As shown in FIGS. 1, 3, and 4, a hydrostatic continuously variable transmission 16 is connected and provided at a front portion of a left side portion 10 b of the transmission case 10. A transmission belt 17 is mounted outside the transmission case 10 over an output shaft 14a of the engine 14 and an input shaft 16a of the hydrostatic continuously variable transmission 16, and the power of the engine 14 The power is transmitted to the hydrostatic continuously variable transmission 16 through the transmission.

[2]
The power of the engine 14 is transmitted to the seedling plant 5 via the hydrostatic continuously variable transmission 16, the first work transmission 32, the second work transmission 37, and the planting transmission shaft 38.
Next, in the transmission system to the seedling planting apparatus 5, the portions from the input shaft 21 to the reverse work clutch 27 and the first work transmission shaft 23 (corresponding to the work transmission shaft) inside the transmission case 10 will be described.

  As shown in FIGS. 3 and 4, the input shaft 16 a and the output shaft 16 b of the hydrostatic continuously variable transmission 16 are arranged in the left-right direction and enter the inside of the transmission case 10. 10 is connected to the front part of the right side part 10a. Inside the transmission case 10, a transmission shaft 19 is connected by a cylindrical connecting member 20 across an input shaft 16 a of the hydrostatic continuously variable transmission 16 and an input shaft 18 a of the hydraulic pump 18.

  The hydraulic pump 18 supplies hydraulic oil to the power steering mechanism 89 (see [11] described later) and the hydraulic cylinder 4, and supplies (charges) hydraulic oil to the hydrostatic continuously variable transmission 16. As shown in FIG. 9, a suction port 10 m is provided at a lower portion of the inner surface of the left side portion 10 b of the transmission case 10, and the lubricating oil of the transmission case 10 is used as hydraulic oil and the hydraulic pump 18 is provided through the suction port 10 m of the transmission case 10. Supplied to

  As shown in FIGS. 3, 4, 5, and 9, the input shaft 21 is supported in the left-right direction near the center in the front-rear direction immediately below the upper portion 10 c of the transmission case 10 in a side view inside the transmission case 10. The output shaft 16 b and the input shaft 21 of the hydrostatic continuously variable transmission 16 are connected via a cylindrical connecting member 22.

  As shown in FIGS. 3, 5, and 9, the first work transmission shaft 23 is supported in a lateral direction at a position slightly below the front side of the input shaft 21 in a side view in parallel with the input shaft 21. A large-diameter gear 24 having a sufficiently large diameter is externally fitted to a portion on the left side (one side) in the longitudinal direction of the first work transmission shaft 23 so as to be relatively rotatable.

  As described in FIGS. 3 and 4 and [7] described later, the power of the input shaft 21 is supplied to the first traveling transmission shaft 49 (the traveling transmission shaft) via the first traveling transmission 50 (corresponding to the traveling transmission). , And a small-diameter gear 114 is connected to the first traveling transmission shaft 49 on the left side (one side) in the longitudinal direction. The large diameter gear 24 and the small diameter gear 114 are engaged.

As shown in FIGS. 3, 5, and 9, the shift member 25 is externally fitted to the first work transmission shaft 23 by a spline structure so as to rotate and slide freely, and biases the shift member 25 to the large-diameter gear 24. 26 are provided.
As described above, the shift member 25 at the left side (one side) of the first work transmission shaft 23 in the longitudinal direction causes the shift member 25 to move between the large-diameter gear 24 and the shift member 25 (the large-diameter gear 24 and the first work transmission). A reverse work clutch 27 is formed between the shaft and the shaft 23).

As shown in FIGS. 3 and 5, when the shift member 25 is slid to the right and engaged with the large-diameter gear 24 (the transmission state of the reverse operation clutch 27), the power of the input shaft 21 is transmitted to the first traveling transmission. 50, the first travel transmission shaft 49, the small-diameter gear 114, the large-diameter gear 24, and the shift member 25 are transmitted to the first work transmission shaft 23. When the shift member 25 is operated to the left and separated from the large-diameter gear 24 (disengagement state of the reverse operation clutch 27), the power of the input shaft 21 is transferred between the large-diameter gear 24 and the shift member 25 (the large-diameter gear 24). And the first work transmission shaft 23).
In this case, as described in [14] described later, the reverse work clutch 27 is operated to be in the transmission state when the vehicle is moving forward, and is operated to be in the disengaged state when the vehicle is moving backward.

  With the above structure, as shown in FIGS. 3 and 5, the power of the engine 14 is controlled by the hydrostatic stepless transmission 16, the input shaft 21, the first traveling transmission 50, the first traveling transmission shaft 49, and the small-diameter gear. The power is transmitted to the first work transmission shaft 23 via the gear 114, the large-diameter gear 24, and the reverse work clutch 27.

[3]
Next, in the transmission system to the seedling planting apparatus 5, a portion from the first work transmission shaft 23 inside the transmission case 10 to the first work transmission 32 (corresponding to the work transmission) will be described.

  As shown in FIGS. 3, 5, and 6, a cylindrical shaft 28 is fitted around the input shaft 21 on the right side (the other side) in the longitudinal direction by a bearing 29 so as to be relatively rotatable (the inner surface of the cylindrical shaft 28 is A plurality (five) of first working gears 30 (corresponding to working gears) that are not in contact with the outer surface of the input shaft 21 are externally fitted to and supported by the cylindrical shaft 28. The plurality of first working gears 30 are connected so as to rotate integrally with each other, and are fitted around the cylindrical shaft 28 and connected.

In this case, as shown in FIG. 6, in the cylindrical bearing holder 28a of the cylindrical shaft 28 to which the bearing 29 is attached, the outer diameter D1 of the bearing holder 28a of the cylindrical shaft 28 is changed to the inner diameter D2 of the first working gear 30 (cylindrical). (Outer diameter of the shaft 28).
As shown in FIGS. 5 and 9, the outer peripheral portion of the large-diameter gear 24 overlaps the outer peripheral portion of the first work gear 30 in a directional view (side view) along the input shaft 21 and the first work transmission shaft 23. ing.

  As shown in FIGS. 3, 5, and 6, a cylindrical member 31 is integrally rotated and slid on the first work transmission shaft 23 by a spline structure on the right side (the other side) in the longitudinal direction of the first work transmission shaft 23. It is externally fitted freely. A small-diameter first gear 31a is provided on the right side (the other side) of the cylindrical member 31 in the longitudinal direction, and a large-diameter second gear is provided on the left side (one side) of the cylindrical member 31 in the longitudinal direction. 31b is provided.

In the state shown in FIGS. 3, 5, and 6, the cylindrical member 31 is slid to the right (the other side), and the second gear 31b of the cylindrical member 31 is moved to the left (one side) of the plurality of first working gears 30. 4) is in a state of being engaged with the first working gear 30a at the end of () (high-speed position H of the first working transmission 32).
When the cylindrical member 31 is slid leftward (one side) from the state shown in FIGS. 3, 5, and 6, the first gear 31a of the cylindrical member 31 is moved to the right side (the other side) of the plurality of first working gears 30. It engages with the first working gear 30b at the end (low-speed position L of the first working transmission 32).

  As shown in FIG. 6, the length L1 of the cylindrical member 31 (first and second gears 31a and 31b) is set to be equal to the length of the first work gear 30 in the row of the plurality of first work gears 30 arranged in the longitudinal direction of the input shaft 21. The length slightly longer than the length L2 of the row of the working gears 30 (the length of the row from the first working gear 30a at the left (one side) end to the first working gear 30b at the right (other side) end). It has become.

  As described above, as shown in FIGS. 3, 5 and 6, the right side (the other side) of the input shaft 21 in the longitudinal direction (the other side) and the right side of the first work transmission shaft 23 in the longitudinal direction. A first work transmission that can be shifted in two stages between the (the other side) portion and the cylindrical member 31 (first and second gears 31a and 31b) and the first work gear 30 (30a and 30b). 32 are configured.

  As shown in FIGS. 3, 5, and 6, in the plurality of first working gears 30, the first working gear 30 a at the left (one side) end of the plurality of first working gears 30 has a minimum diameter. The first working gear 30b at the right end (the other side) of the first working gear 30 has a maximum diameter. The first gear 31a of the cylindrical member 31 has a small diameter, and the second gear 32b of the cylindrical member 31 has a large diameter.

  Thereby, as shown in FIG. 6, the cylindrical member 31 is slid to the right (the other side) to move the second gear 31b of the cylindrical member 31 to the left side (one side) of the plurality of first working gears 30. (The high-speed position H of the first working transmission 32), the first gear 31a of the cylindrical member 31 is engaged with the bearing holder of the bearing 98 of the input shaft 21 in the transmission case 10. No contact with 10e.

  With the above structure, as shown in FIGS. 3, 5, and 6, the power of the first work transmission shaft 23 is transmitted to the first work transmission 32 (the cylindrical member 31 (the first and second gears 31a and 31b) and the first work transmission 32). The power is transmitted to the working gear 30 (30a, 30b) and the cylindrical shaft 28), and the speed is shifted to two stages.

[4]
Next, in the transmission system to the seedling planting apparatus 5, a portion from the first work transmission 32 to the second work transmission 37 inside the transmission case 10 will be described.

  As shown in FIGS. 3, 5, and 9, a second work transmission shaft 33 is provided between the input shaft 21 and the first work transmission shaft 23 immediately below the upper portion 10 c of the transmission case 10 and on the rear side of the input shaft 21 in a side view. It is supported in the left and right direction in parallel.

  As shown in FIGS. 3, 5, and 6, a cylindrical portion 33 a is formed on the right side (the other side) of the second work transmission shaft 33 in the longitudinal direction, and a plurality (four) of the second work gears 34. Are fitted to the cylindrical portion 33a of the second work transmission shaft 33 so as to be relatively rotatable. Each of the first working gears 30 (excluding the first working gear 30b at the right end (the other side) of the plurality of first working gears 30) and each of the second working gears 34 are engaged. .

  As shown in FIG. 6, a hole is formed in the cylindrical portion 33a of the second working transmission shaft 33 corresponding to the second working gear 34 in a radial direction, and a ball member 35 is formed in the hole in the radial direction. It is provided movably. An operating shaft 36 is slidably provided on the cylindrical portion 33a of the second work transmission shaft 33, and a large-diameter portion 36a is provided on the tip of the operating shaft 36.

  As shown in FIG. 6, when the ball member 35 is pushed radially outward by the large diameter portion 36a of the operation shaft 36, the ball member 35 is moved to the cylindrical portion 33a of the second work transmission shaft 33 and the second work gear 34. The second working gear 34 is connected to the cylindrical portion 33 a of the second working transmission shaft 33.

As shown in FIG. 6, in a portion other than the large diameter portion 36 a of the operation shaft 36, the ball member 35 moves away from the second work gear 34 toward the center in the radial direction, and the cylindrical portion of the second work transmission shaft 33 is moved. The state where the second working gear 34 is not connected to 33a is brought into a state.
By sliding the operation shaft 36 in this manner, power is transmitted from the first work gear 30 to the second work transmission shaft 33 in the second work gear 34 connected to the cylindrical portion 33a of the second work transmission shaft 33. Is done.

  As described above, as shown in FIGS. 3, 5, and 6, the right side (the other side) of the input shaft 21 in the longitudinal direction (the other side) and the right side of the second work transmission shaft 33 in the longitudinal direction. The first and second working gears 30 and 34 constitute a second working transmission 37 that can be shifted in four stages between the first working gear 30 and the other working gear.

As shown in FIG. 6, in the second work transmission 37, the second work gear 34 at the right (other side) end of the plurality of second work gears 34 is connected to the cylindrical portion of the second work transmission shaft 33. The state connected to 33a is the first speed position F1.
The state in which the second second working gear 34 from the right (the other side) end of the plurality of second working gears 34 is connected to the cylindrical portion 33a of the second working transmission shaft 33 corresponds to the second speed position F2. Become.
A state in which the third second working gear 34 from the right end (the other side) of the plurality of second working gears 34 is connected to the cylindrical portion 33a of the second working transmission shaft 33 corresponds to the third speed position F3. Become.
A state in which the fourth second working gear 34 from the right end (the other side) of the plurality of second working gears 34 is connected to the cylindrical portion 33a of the second working transmission shaft 33 corresponds to the fourth speed position F4. Become.
The first speed position F1 is the highest speed position, the second speed position F2 is lower than the first speed position F1, the third speed position F3 is lower than the second speed position F2, and the fourth speed position F4 is the lowest speed position.

  With the above structure, as shown in FIGS. 3, 5, and 6, the power of the first work transmission 32 is transmitted to the second work transmission 37 (the first and second work gears 30 and 34) and And transmitted to the second work transmission shaft 33.

[5]
Next, in the transmission system to the seedling planting apparatus 5, a portion from the second work transmission 37 to the seedling planting apparatus 5 will be described.

  As shown in FIGS. 3, 5, and 9, a planting transmission shaft 38 is supported in a front-rear direction at an upper portion of a rear portion of the transmission case 10. And is located at the rear side of the second work transmission shaft 33. The planting transmission shaft 38 is located at the left-right center CL of the body in plan view, and is arranged to be orthogonal to the second work transmission shaft 33.

  As shown in FIGS. 1, 10, and 11, right and left body frames 45 are connected to the rear of the transmission case 10 and extend rearward, and a rear axle is provided at the rear of the right and left body frames 45. A case 12 is supported. The planting transmission shaft 38 is arranged between the right and left body frames 45 in a plan view, and is arranged at the same height so as to overlap the right and left body frames 45 in a side view.

  As shown in FIG. 1, a transmission shaft (not shown) connected to the planting transmission shaft 38 extends rearward between the right and left body frames 45 in a plan view, and extends right and left in a side view. It extends rearward at the same height so as to overlap the left body frame 45. A transmission shaft 47 connected to a rear portion of the aforementioned transmission shaft (not shown) extends rearward and is connected to an input shaft (not shown) of the seedling planting apparatus 5.

  As shown in FIGS. 3, 5, and 9, a bevel gear 39 is connected to the left (one side) end of the second work transmission shaft 33 in the longitudinal direction. A boss member 48 is fitted to the planting transmission shaft 38 so as to be relatively rotatable, a bevel gear 40 is connected to the boss member 48, and the bevel gears 39 and 40 are engaged.

As shown in FIGS. 3, 5, and 9, a shift member 41 is externally fitted to the planting transmission shaft 38 by a spline structure so that the shift member 41 can rotate and slide freely, and a spring 42 that urges the shift member 41 to the bevel gear 40. An operation shaft 43 for moving the shift member 41 away from the bevel gear 40 and an operation arm 46 for sliding the operation shaft 43 are provided.
As described above, the planting clutch 44 is configured between the bevel gear 40 and the shift member 41 by the shift member 41.

  As shown in FIGS. 3 and 5, when the operation shaft 43 is slid to the right (the other side), the shift member 41 is slid forward by the spring 42 to engage with the boss member 48 (bevel gear 40) (planting). Transmission state of clutch 44). Thereby, the power of the second work transmission shaft 33 is transmitted to the planting transmission shaft 38 via the bevel gears 39 and 40 and the boss member 48.

As shown in FIGS. 3 and 5, when the operation shaft 43 is operated to the left (one side), the shift member 41 is separated from the boss member 48 (bevel gear 40) by the operation shaft 43 (the disengagement state of the planting clutch 44). ). Thereby, the power of the second work transmission shaft 33 is cut off between the shift member 41 and the boss member 48 (bevel gear 40).
With the above structure, as shown in FIGS. 1, 3, and 5, the power of the second work transmission shaft 33 is transmitted to the seedling planting device 5 via the planting clutch 44, the planting transmission shaft 38, and the transmission shaft 47. Is done.

[6]
Next, in the transmission system to the seedling planting apparatus 5, the entire speed change ranges R1 and R2 of the first and second work transmissions 32 and 37 will be described.

  The speed of the power transmitted to the seedling planting device 5 means an interval (between plants) in the front-rear direction of the seedlings to be planted on the rice field by the planting arm 8. As the speed increases, the rotating case 7 is driven to rotate at a higher speed, and the distance between the stocks becomes smaller (narrower).

  As described in the preceding paragraph [3], the first work transmission 32 can be freely shifted to two stages of high and low speed positions H and L, and as described in the preceding paragraph [4], the second work transmission 37 is The first and second working transmissions 32 and 37 can be freely shifted to eight speeds because the speed can be changed to four speeds of the first to fourth speed positions F1 to F4.

In this case, as shown in FIG. 6 and FIG.
The state where the first work transmission 32 is in the high-speed position H and the second work transmission 37 is in the first-speed position F1 is defined as the first-speed position FF1 of the first and second work transmissions 32 and 37.
The state where the first work transmission 32 is in the high speed position H and the second work transmission 37 is in the second speed position F2 is defined as the second speed position FF2 of the first and second work transmissions 32 and 37.
The state where the first work transmission 32 is in the high speed position H and the second work transmission 37 is in the third speed position F3 is defined as the third speed position FF3 of the first and second work transmissions 32 and 37.
The state where the first work transmission 32 is in the high speed position H and the second work transmission 37 is in the fourth speed position F1 is defined as the fourth speed position FF4 of the first and second work transmissions 32 and 37.
The state where the first work transmission 32 is in the low speed position L and the second work transmission 37 is in the first speed position F1 is defined as the fifth speed position FF5 of the first and second work transmissions 32 and 37.
The state where the first work transmission 32 is in the low speed position L and the second work transmission 37 is in the second speed position F2 is defined as the sixth speed position FF6 of the first and second work transmissions 32 and 37.
The state where the first work transmission 32 is in the low speed position L and the second work transmission 37 is in the third speed position F3 is defined as the seventh speed position FF7 of the first and second work transmissions 32 and 37.
The state where the first work transmission 32 is in the low speed position L and the second work transmission 37 is in the fourth speed position F4 is defined as the eighth speed position FF8 of the first and second work transmissions 32 and 37.

  As shown in FIG. 15, the entire speed range R1 of the first speed position FF1 to the fourth speed position FF4 of the first and second work transmissions 32 and 37 (the second gear 31b of the cylindrical member 31 in the first work transmission 32). Is engaged with the first work gear 30a at one end of the plurality of first work gears 30, and the second work transmission 37 is moved to each of the shift positions (first to fourth speed positions F1 to F4). ) Is assumed to be the entire shift range R1) of the first and second working transmissions 32 and 37.

  As shown in FIG. 15, the entire shift range R2 of the fifth speed position FF5 to the eighth speed position FF8 of the first and second work transmissions 32 and 37 (the first gear 31a of the cylindrical member 31 in the first work transmission 32). Is engaged with the first working gear 30b at the other end of the plurality of first working gears 30, and the second work transmission 37 is moved to each shift position (first to fourth speed positions F1 to F4). ) Is assumed to be the entire shift range R2) of the first and second work transmissions 32 and 37.

  In this case, as shown in FIG. 15, the first speed position FF1 of the first and second work transmissions 32, 37 is the highest speed position (the minimum distance between stocks), and the first and second work transmissions 32, 37 The lower the speed is in the second, third, fourth, fifth, sixth, and seventh speed positions FF2 to FF7, the lower the speed (because the interval between the stocks increases), and the first and second working transmissions 32, 37 The eighth speed position FF8 is the lowest speed position (the maximum is between stocks).

  As shown in FIGS. 6 and 15, the two shift ranges R1 and R2 are separated from each other so that they do not overlap with each other (the first and second shift speeds FF5 of the first and second working transmissions 32 and 37 are higher than the first and second shift speeds FF5). The speed ratio of the first work transmission 32 at the high speed position H and the speed ratio of the low speed position L are set so that the fourth speed position FF4 of the work transmissions 32 and 37 becomes high speed. The gear ratio of the first speed position F1, the gear ratio of the second speed position F2, the gear ratio of the third speed position F3, and the gear ratio of the fourth speed position F4 are set.

[7]
The power of the engine 14 is transmitted from the hydrostatic continuously variable transmission 16, the first traveling transmission 50, and the second traveling transmission 57 to the front wheels 1 and the rear wheels 2 via the front wheel differential mechanism 73 and the rear wheel transmission shaft 59. Is transmitted.
Next, in the transmission system to the front wheels 1 and the rear wheels 2, a portion of the first traveling transmission 50 from the input shaft 21 inside the transmission case 10 will be described.

  As shown in FIGS. 3, 4, 5, and 7, on the left (one side) portion of the input shaft 21 in the longitudinal direction, the first shift gear 51 is integrally rotatable and slidably attached to the input shaft 21 by a spline structure. It is fitted. The first shift gear 51 includes a low-speed gear 51a and a high-speed gear 51b.

As shown in FIGS. 3, 4, 7, and 9, a first traveling transmission shaft 49 is supported in the left and right direction parallel to the input shaft 21 at a position slightly below the input shaft 21 in a side view. .
A middle-speed traveling gear 54 (corresponding to a traveling gear) is connected to an end on the left side (one side) of the first traveling transmission shaft 49 in the longitudinal direction, and the right side (the other side) of the first traveling transmission shaft 49 in the longitudinal direction. A low-speed traveling gear 53 (corresponding to a traveling gear) is connected to an end of the first traveling power transmission shaft 49 and a high-speed traveling gear 55 (corresponding to a traveling gear) at a central portion in the longitudinal direction of the first traveling transmission shaft 49. ) Are connected.

  The state shown in FIGS. 3 and 7 is a state in which the first shift gear 51 is slid to the right (the other side), and the high-speed gear 51b of the first shift gear 51 is engaged with the high-speed traveling gear 55 (first traveling speed change). High-speed position of the device 50). When the first shift gear 51 is slid to the left (one side) from the state shown in FIGS. 3 and 7, the low-speed gear 51a of the first shift gear 51 engages with the medium-speed traveling gear 54 (the low-speed gear of the first traveling transmission 50). position).

As described above, as shown in FIGS. 4 and 7, the left side (one side) of the input shaft 21 in the longitudinal direction and the left side (one side) of the first traveling transmission shaft 49 in the longitudinal direction. The first shift member 51 and the medium-speed and high-speed traveling gears 54 and 55 constitute a first traveling transmission 50 that can be shifted in two stages.
With the above structure, the power of the input shaft 21 is transmitted to the first traveling transmission 50 (the first shift gear 51, the medium-speed and high-speed traveling gears 54 and 55), and the speed is changed to two stages, so that the first traveling transmission shaft is transmitted. 49.

[8]
Next, in the transmission system to the front wheels 1 and the rear wheels 2, a portion from the first traveling transmission 50 to the second traveling transmission 57 inside the transmission case 10 will be described.

  As shown in FIGS. 3, 4, and 9, at a position slightly below the first traveling transmission shaft 49 in a side view, the second traveling transmission shaft 56 is connected to the input shaft 21 and the first traveling transmission shaft 49. It is supported in the left and right direction in parallel.

  As shown in FIGS. 3 and 4, the second shift gear 52 is integrally rotated and slid on the second traveling transmission shaft 56 by a spline structure at a portion on the right side (the other side) in the longitudinal direction of the second traveling transmission shaft 56. It is externally fitted freely. The second shift gear 52 includes a low-speed gear 52a and a high-speed gear 52b.

  The state shown in FIG. 3 is a state in which the second shift gear 52 is slid to the left (one side), and the high-speed gear 52b of the second shift gear 51 is engaged with the high-speed traveling gear 55 (the second traveling transmission 57). Fast position). When the second shift gear 52 is slid rightward (to the other side) from the state shown in FIG. 3, the low-speed gear 52a of the second shift gear 52 meshes with the low-speed traveling gear 53 (the low-speed position of the second traveling transmission 57).

As described above, as shown in FIGS. 3 and 4, the right side (the other side) of the first traveling transmission shaft 49 in the longitudinal direction and the right side (the other side) of the second traveling transmission shaft 56 in the longitudinal direction. The second shift gear 52 and the low-speed and high-speed traveling gears 53 and 55 constitute a second traveling transmission 57 that can be freely shifted in two stages.
With the above structure, the power of the first travel transmission shaft 49 is transmitted to the second travel transmission 57 (the second shift gear 52, the low-speed and high-speed travel gears 53 and 55), and is shifted to two speeds, so that the second travel is performed. The power is transmitted to the transmission shaft 56.

As shown in FIGS. 3 and 4, the high-speed traveling gear 55 is a traveling gear corresponding to the high-speed position (highest-speed position) of the first traveling transmission 50, and the high-speed traveling gear (the highest-speed position) of the second traveling transmission 57. Position), and is a common component of the first and second traveling transmissions 50 and 57.
Since the high-speed running gear 55 is provided at a central portion of the first running transmission shaft 49 in the longitudinal direction, the high-speed gear 51b of the first shift gear 51 is engaged with the high-speed running gear 55, and the second shift gear 52 By engaging the high-speed gear 52b with the high-speed traveling gear 55, the highest speed positions of the first and second traveling transmissions 50 and 57 can be obtained. The highest speed positions of the first and second traveling transmissions 50 and 57 are generally used when traveling on a road.

In this case, as shown in FIG. 3 and FIG. 4, the first shift gear 51 (high-speed gear 51 b), the high-speed travel gear 55, and the second shift gear 52 ( The high-speed gears 52b) are in a line.
The small-diameter gear 114, the reverse working clutch 27 (large-diameter gear 24), the first traveling transmission 32 are disposed on the left side (one side), and the second traveling transmission 37 is located on the right side, with the high-speed traveling gear 55 as a boundary in plan view. (The other side).

[9]
Next, in the transmission system to the front wheels 1 and the rear wheels 2, a portion from the second traveling transmission 57 to the rear wheel transmission shaft 59 inside the transmission case 10 will be described.

  As shown in FIGS. 3 and 8, a bevel gear 58 (corresponding to a first bevel gear) is connected to an end of the second traveling transmission shaft 56 on the left side (one side) in the longitudinal direction, and the bevel gear 58 (tooth portion) is connected. ) Faces the second shift member 52.

  Thereby, as shown in FIGS. 3 and 8, of the low-speed, medium-speed, and high-speed running gears 53, 54, and 55, the left (one side) end of the first running transmission shaft 49 in the longitudinal direction is provided. The bevel gear 58 is connected to the second traveling transmission shaft 56 so that the bevel gear 58 (tooth portion) faces the second shift member 52 so that the bevel gear 58 is located outside (to the left of) the located medium-speed traveling gear 54. ing.

  As shown in FIGS. 3, 8 and 9, a rear wheel transmission shaft 59 is supported in the front and rear direction at a lower portion of a rear portion of the transmission case 10, and the rear wheel transmission shaft 59 is formed of the planting transmission shaft 38 in a side view. It is arranged so as to be located on the lower side and at the same height as the second traveling transmission shaft 56. The rear wheel transmission shaft 59 is located at the left-right center CL of the body in plan view, and is disposed so as to be orthogonal to the second traveling transmission shaft 56.

  As shown in FIGS. 3, 8, and 9, a bevel gear 60 (corresponding to a second bevel gear) is connected to the rear wheel transmission shaft 59 by a spline structure, and the bevel gears 58 and 60 are engaged. A transmission shaft (not shown) connected to a rear portion of the rear wheel transmission shaft 59 extends rearward and is connected to an input shaft (not shown) of the rear axle case 12.

  With the above structure, as shown in FIGS. 3 and 8, the power of the second traveling transmission shaft 56 is transmitted to the rear axle case 12 via the bevel gears 58 and 60 and the rear wheel transmission shaft 59, and The power is transmitted to the right and left rear wheels 2 via a transmission shaft (not shown) and a transmission gear (not shown) inside the rear wheel 2.

As shown in FIG. 8, the left end (one side) (bevel gear 58 side) end of the second traveling transmission shaft 56 in the longitudinal direction is supported by two bearings 62. The right end (the other side) of the second traveling transmission shaft 56 in the longitudinal direction (the second shift gear 52 side) is supported by a single bearing 63.
In this case, as shown in FIG. 3, the bevel gear 60 is located between the bevel gear 58 and the second shift gear 52 in rear view, and the medium-speed traveling gear 54 is on the left side (one side) with respect to the bevel gear 60. And the high-speed running gear 55 is arranged on the right side (the other side).

[10]
Next, the rear wheel transmission shaft 59 will be described.

  As shown in FIGS. 8 and 9, the boss 60 a of the bevel gear 60 is extended, and the boss 60 a of the bevel gear 60 is supported by the bearing 64. Are in contact with the bearing 64. An intermediate portion of the rear wheel transmission shaft 59 is supported by a bearing 65.

  As shown in FIGS. 8 and 9, a brake plate 66 is externally fitted to the boss portion 60 a of the bevel gear 60 so as to rotate and slide integrally with the boss portion 60 a of the bevel gear 60 by a spline structure. And a ring-shaped receiving member 67 is provided. A ring-shaped pressing member 68 is fitted on the rear wheel transmission shaft 59 so as to slide and relatively rotate. As described above, the brake 69 is constituted by the brake plate 66 and the pressing member 68.

As shown in FIGS. 8 and 9, the brake operation shaft 70 is rotatably supported by the transmission case 10, and the operation part 70 a of the brake operation shaft 70 having a 円 circular cross section is located below the pushing member 68. Have been assigned.
As shown in FIGS. 10 and 11, the brake pedal shaft 71 to which the brake pedal 61 is connected is disposed between the planting transmission shaft 38 and the rear wheel transmission shaft 59 in a side view, and is disposed in the left-right direction. (The planting transmission shaft 38 is disposed above the brake pedal shaft 71 in a side view). A link rod 72 is connected to an arm 70b of the brake operation shaft 70 and an arm 71a of the brake pedal shaft 71.

With the above-described structure, when the brake pedal 61 is depressed, the brake pedal shaft 71 is rotated by a small angle, and the brake operation shaft 70 is also rotated by a small angle via the link rod 72. The pressing member 68 is pressed against the brake plate 66 by the operating portion 70a of the shaft 70, and the brake 69 is operated in the braking state.
In this case, as described in [11] to be described later, since a transmission system to the right and left front wheels 1 is configured, in addition to braking the right and left rear wheels 2 by the brake 69, The right and left front wheels 1 are also braked.

  As shown in FIG. 8, when the bevel gear 60 is connected to the rear wheel transmission shaft 59 by a spline structure, the fitting of the spline portion between the bevel gear 60 and the rear wheel transmission shaft 59 is set to be hard (large). In this state, the bevel gear 60 and the rear wheel transmission shaft 59 are rigidly connected.

  Thus, when the rear wheel transmission shaft 59 is pulled out to the rear side in a state where the bearing 65 and the brake operation shaft 70 shown in FIG. 8 are removed, the bevel gear 60 is pulled out together with the rear wheel transmission shaft 59. Along with 60, the bearing 64 and the brake 69 (the brake plate 66 and the pushing member 68) are extracted together.

[11]
Next, in the transmission system to the front wheel 1 and the rear wheel 2, a portion from the second traveling transmission 57 to the front wheel differential mechanism 73 inside the transmission case 10 and the steering mechanism of the front wheel 1 will be described.

  As shown in FIGS. 4 and 9, inside the transmission case 10, a steering shaft 74 is rotatably supported in the vertical direction along the front wall 10 d of the transmission case 10, and is disposed. A pinion gear 74a is provided at a lower part of the gear.

  As shown in FIGS. 9, 10, 11, and 12, a hydraulic power steering mechanism 89 is connected to a front portion of an upper portion 10c of the transmission case 10, and an output shaft (not shown) of the power steering mechanism 89 is connected to a steering wheel. The upper part of the shaft 74 is connected. A handle shaft 90 extends upward from the power steering mechanism 89, and a steering handle 75 (see FIGS. 1 and 2) is connected to an upper portion of the handle shaft 90.

As shown in FIG. 9, an operation shaft 76 is rotatably supported in the bottom portion 10 f of the transmission case 10 on the rear side of the pinion gear 74 a of the steering shaft 74 in the vertical direction. 76a and the pinion gear 74a of the steering shaft 74 are engaged. A steering member 91 is connected to a lower portion of the operation shaft 76, and the steering member 91 is connected to support cases (not shown) of the right and left front wheels 1 by tie rods 92.
Thus, when the steering handle 75 is operated, the steering shaft 74 is rotated, the operation shaft 76 is rotated, and the front wheels 1 are steered.

  As shown in FIGS. 4 and 9, a steering shaft 74 as a steering mechanism of the front wheel 1, a pinion gear 74 a of the steering shaft 74, an operation shaft 76, and an operation gear 76 a of the operation shaft 76 are connected to a front wall 10 d of the transmission case 10. And it is in a state of being arranged along the bottom 10f of the transmission case 10.

  As shown in FIG. 9, the bottom 10 f of the transmission case 10 is in a rearward downward shape (the rear part of the bottom 10 f of the transmission case 10 is lower than the front part of the bottom 10 f of the transmission case 10). Similarly, the operating gear 76a of the operating shaft 76 is also lowered rearward along the bottom 10f of the transmission case 10 (the rear part of the operating gear 76a of the operating shaft 76 is more rearward than the front part of the operating gear 76a of the operating shaft 76). Bottom).

  As shown in FIGS. 4 and 9, in a state in which a virtual line K1 extending upward from the axis of the operation shaft 76 is set, the front wheel differential mechanism 73 is located behind the virtual line K1 in a side view, and The operation shaft 76 is arranged at a position above the operation gear 76 a. The front wheel differential mechanism 73 overlaps a rear portion of the operation gear 76a of the operation shaft 76 in a plan view, and is disposed at a position at a center CL on the right and left sides of the body. The second traveling transmission shaft 56 is disposed above the front wheel differential mechanism 73 and rearward in a side view.

  As shown in FIGS. 3, 4, and 9, a transmission gear 77 is connected to the right end (the other side) of the second traveling transmission shaft 56 in the longitudinal direction, and is disposed in the case 3 a of the front wheel differential mechanism 73 in the longitudinal direction. The transmission gear 78 is connected to the right end (the other side) of the transmission gear 77, and the transmission gears 77 and 78 are engaged.

  As shown in FIGS. 3, 4, and 9, the right (left) front wheel transmission shaft 79 extends right (left) from the front wheel differential mechanism 73, and the right (left) front wheel transmission shaft 79 extends right (left). Are connected to the front wheel 1 of the vehicle. Since the front wheel differential mechanism 73 is disposed at the position of the left-right center CL of the body in plan view, the lengths of the right and left front wheel transmission shafts 79 are the same.

  Thereby, as shown in FIGS. 3 and 4, the power of the second traveling transmission shaft 56 is transmitted to the front wheel differential mechanism 73 (case 73 a) via the transmission gears 77 and 78, and is transmitted from the front wheel differential mechanism 73 to the right ( The power is transmitted to the right (left) front wheel 1 via the left (left) front wheel transmission shaft 79.

[12]
Next, inside the transmission case 10, the input shaft 21, the first and second working transmission shafts 23 and 33, the first and second traveling transmission shafts 49 and 56, the planting transmission shaft 38, the rear wheel transmission shaft 59, The positional relationship between the front wheel differential mechanism 73 (the front wheel transmission shaft 79) will be described (part 1).

As shown in FIG. 9, the input shaft 21 is supported in the left-right direction near the center in the front-rear direction immediately below the upper portion 10c of the transmission case 10 in a side view (see the preceding section [2]). At a position slightly below the front side of the input shaft 21 in a side view, the first work transmission shaft 23 is supported in the left-right direction (see the preceding item [2]).
A second work transmission shaft 33 is supported in the left and right direction on the rear side of the input shaft 21 immediately below the upper portion 10c of the transmission case 10 in a side view (see the preceding item [4]).

As shown in FIG. 9, the first traveling transmission shaft 49 is supported in the left-right direction at a position slightly behind the input shaft 21 (rear side of the first work transmission shaft 23) in a side view (see FIG. 9). Refer to the previous section [7]).
A second traveling power transmission shaft 56 is supported in the left-right direction at a position slightly below the first traveling power transmission shaft 49 in a side view (see the preceding item [8]).

As shown in FIG. 9, the front wheel differential mechanism 73 is located behind the imaginary line K <b> 1 (when the axis of the operation shaft 76 is extended upward (see [11] above)) in a side view and at the operation shaft. The operation gear 76a is disposed at a position above the operation gear 76a, overlaps with a rear portion of the operation gear 76a of the operation shaft 76 in a plan view, and is disposed at a position at a center CL on the right and left sides of the body (see the preceding item [11]). .
The second traveling transmission shaft 56 is disposed above and behind the front wheel differential mechanism 73 in a side view (see [11] above).

  As shown in FIG. 9, the input shaft 21, the first work transmission shaft 23, the second work transmission shaft 33, the first travel transmission shaft 49, the second travel transmission shaft 56, and the front wheel differential mechanism 3 (the front wheel transmission shaft 79) , Arranged in the left-right direction and in parallel with each other.

As shown in FIG. 9, at the upper part of the rear part of the transmission case 10, a planting transmission shaft 38 is supported in a front-rear direction, and the planting transmission shaft 38 has the same height as the second work transmission shaft 33 in a side view. And is disposed so as to be located on the rear side of the second work transmission shaft 33.
The planting transmission shaft 38 is disposed at the left-right center CL of the body in plan view, and is disposed so as to be orthogonal to the second work transmission shaft 33 (see the preceding section [5]).

As shown in FIG. 9, a rear wheel transmission shaft 59 is supported in the front and rear direction at a lower portion of a rear portion of the transmission case 10, and the rear wheel transmission shaft 59 is disposed below the planting transmission shaft 38 in a side view. And it is arrange | positioned so that it may be located in the same height as the 2nd drive transmission shaft 56.
The rear wheel transmission shaft 59 is disposed at the left-right center CL of the vehicle body in a plan view, and is disposed so as to be orthogonal to the second traveling transmission shaft 56 (see the preceding section [9]).

  As shown in FIG. 9, the planting transmission shaft 38 and the rear wheel transmission shaft 56 are arranged in the front-rear direction and parallel to each other, and the first work transmission shaft 23, the second work transmission shaft 33, and the first The drive transmission shaft 49, the second drive transmission shaft 56, and the front wheel differential mechanism 3 (the front wheel transmission shaft 79) are disposed so as to be orthogonal to each other in plan view.

[13]
Next, inside the transmission case 10, the input shaft 21, the first and second working transmission shafts 23 and 33, the first and second traveling transmission shafts 49 and 56, the planting transmission shaft 38, the rear wheel transmission shaft 59, The positional relationship between the front wheel differential mechanism 73 (the front wheel transmission shaft 79), the first work transmission 32, and the first traveling transmission 50 will be described (part 2).
The configuration described in [12] above has the following configuration.

  As shown in FIG. 9, the input shaft 21, the second work transmission shaft 33, and the planting transmission shaft 38 are arranged at substantially the same height in a side view. The first work transmission shaft 23 and the first travel transmission shaft 49 are disposed at substantially the same height below the input shaft 21 and the second work transmission shaft 33 in a side view.

  As shown in FIG. 9, the second traveling transmission shaft 56 is disposed above and behind the front wheel differential mechanism 73 (the front wheel transmission shaft 79) in a side view, and has the same height as the second traveling transmission shaft 56. A rear wheel transmission shaft 59 is disposed behind the two traveling transmission shaft 56. As a result, the front wheel differential mechanism 73 (the front wheel transmission shaft 79) is disposed on the front side of the engaging portion between the bevel gear 58 of the second traveling transmission shaft 56 and the bevel gear 60 of the rear wheel transmission shaft 59 in side view.

  As shown in FIG. 9, the input shaft 21, the first work transmission shaft 23, the reverse work clutch 27, the first travel transmission shaft 49, the front wheel differential mechanism 73 (the front wheel transmission shaft 79), the first and second work transmissions 32. , 37, and the first and second traveling transmissions 50, 57 are provided with a virtual line K1 (in which the axis of the operation shaft 76 extends upward (see [11] above)) and a transmission case 10 in side view. It is arranged between the rear wall portion 10p and above a rear portion of the operation gear 76a of the operation shaft 76.

As shown in FIG. 9, the input shaft 21, the first and second work transmission shafts 23 and 33, the first and second traveling transmission shafts 49 and 56, the planting transmission shaft 38, and the rear wheel transmission shaft 59 in side view. The front wheel differential mechanism 73 (the front wheel transmission shaft 79), the first and second work transmissions 32 and 37, and the first and second travel transmissions 50 and 57 are disposed at a position slightly away from the steering shaft 74 and on the rear side. .
Thereby, in side view, the input shaft 21, the first and second work transmission shafts 23 and 33, the first and second traveling transmission shafts 49 and 56, the planting transmission shaft 38, the rear wheel transmission shaft 59, and the front wheel differential mechanism. 73 (front wheel transmission shaft 79), the first and second working transmissions 32 and 37, the first and second traveling transmissions 50 and 57, and the front shaft portion 10d of the transmission case 10, a steering shaft 74 is provided. They are arranged vertically.
4 and 9, the rear wheel transmission shaft 59 is arranged such that the outer peripheral portion of the bevel gear 60 of the rear wheel transmission shaft 59 overlaps the outer peripheral portion of the front wheel differential mechanism 73 (case 73a) in a front view. Have been.

[14]
Next, the operation system of the reverse work clutch 27 will be described.

  As shown in FIGS. 3 and 9, inside the transmission case 10, the input shaft 16 a and the output shaft 16 b of the hydrostatic continuously variable transmission 16 are arranged side by side in a side view in a state where the input shaft 16 a and the output shaft 16 b are oriented in the left-right direction. Are located. Thus, the transmission shaft 19 connected to the input shaft 16a of the hydrostatic continuously variable transmission 16 and the input shaft 21 connected to the output shaft 16b of the hydrostatic continuously variable transmission 16 are oriented in the left-right direction. In the state, they are arranged side by side in a side view.

  As shown in FIG. 9, inside the transmission case 10, a clutch shaft 80 is provided on a boss 10 g of an upper portion 10 c of the transmission case 10 and a support portion 10 h on an inner surface of a left portion 10 b of the transmission case 10. The clutch shaft 80 is rotatably supported around the core P <b> 1, and the upper portion of the clutch shaft 80 projects outward (upward) from the boss 10 g of the transmission case 10. A bifurcated clutch fork 80a is connected to the lower portion of the clutch shaft 80. The clutch fork 80a extends rearward toward the reverse work clutch 27 and is engaged with the shift member 25.

As shown in FIG. 9, an arm 80b is connected to an upper portion of the clutch shaft 80, and the arm 80b is connected to a shift lever 81 (FIG. 1) of the hydrostatic continuously variable transmission 16 via a link (not shown). And FIG. 2).
As described above, the clutch operating portion 82 of the reverse work clutch 27 is constituted by the clutch shaft 80 and the clutch fork 80a of the clutch shaft 80.

  The hydrostatic continuously variable transmission 16 is configured to be capable of continuously variable transmission in a forward region and a reverse region with a neutral region interposed therebetween. As shown in the previous section [2] and FIGS. 5 and 9, when the shift lever 81 is operated in the forward area (at the time of forward movement) and in the forward area of the neutral area, the shift member 25 meshes with the large-diameter gear 24. Thus, the reverse work clutch 27 is in the transmission state.

  As shown in the previous section [2] and FIGS. 5 and 9, when the shift lever 81 is operated from the forward portion to the reverse portion of the neutral region, the clutch shaft 80 is rotated by the shift lever 81 and the clutch shaft 80 is moved. The shift member 25 is separated from the large-diameter gear 24 by the clutch fork 80a, and the reverse operation clutch 27 is brought into a disconnected state. Even if the speed change lever 81 is operated from the backward portion of the neutral region to the reverse region (during reverse), the disengagement state of the reverse work clutch 27 is maintained (see the preceding section [2]).

As shown in FIGS. 5 and 9, the clutch operation unit 82 (the clutch shaft 80) includes a first work transmission 32 (the input shaft 21, the cylindrical shaft 28, the first work transmission shaft 23) and a steering shaft in a side view. 74.
The clutch shaft 80 is disposed between the input shaft 16a (the transmission shaft 19) and the output shaft 16b (the input shaft 21) of the hydrostatic continuously variable transmission 16 in a side view, and is provided on the upper portion 10c of the transmission case 10. It protrudes upward from the boss 10g. The clutch shaft 80 is arranged between the transmission shaft 19 and the input shaft 21 in plan view.

As shown in FIGS. 9, 11, and 12, an arm 80b is connected to an upper portion of the clutch shaft 80 by a nut 86. By removing the nut 86, the arm 80b can be removed from the clutch shaft 80.
By removing the arm 80b from the clutch shaft 80 in this manner, the seal member 87 of the boss 10g of the transmission case 10 can be pulled upward along the clutch shaft 80, and the seal member 87 can be easily replaced. be able to.

[15]
Next, an operation system of the first traveling transmission 50 will be described.

  As shown in FIGS. 7 and 9, inside the transmission case 10, the first traveling boss 10 i on the inner surface of the right side 10 a of the transmission case 10 and the boss 10 j on the inner surface of the left side 10 b of the transmission case 10 are provided with the first traveling. The shift shaft 83 is slidably supported in the left-right direction. A first traveling fork 83a is connected to an intermediate portion of the first traveling shift shaft 83. The first traveling fork 83a extends rearward toward the first traveling transmission 50 and engages with the first shift gear 51. I agree.

As shown in FIGS. 7 and 9, an operation shaft 84 is rotatably supported by a boss 10 k of an upper portion 10 c of the transmission case 10 around a vertical axis P <b> 2. It protrudes outside (upper side) from the boss portion 10k of 10. Inside the transmission case 10, a bifurcated arm 84a is connected to a lower portion of the operation shaft 84, and the arm 84a extends rearward toward the first travel shift shaft 83, and the first travel shift shaft 83 Is engaged with the small diameter portion 83b.
As described above, the first traveling shift unit 83 of the first traveling transmission 50 is constituted by the first traveling shift shaft 83 (first traveling fork 80a) and the operating shaft 84 (arm 84a).

  As shown in the preceding section [7] and FIGS. 7 and 9, when the first traveling shift shaft 83 is slid to the left (one side) by the operating shaft 84, the first traveling shift shaft 83 (the first traveling fork 83a). As a result, the first shift gear 51 is slid to the left (one side), and the low-speed gear 51a of the first shift gear 51 is engaged with the medium-speed traveling gear 54 (the low-speed position of the first traveling transmission 50).

As shown in the previous section [7] and FIGS. 7 and 9, when the first traveling shift shaft 83 is slid to the right (the other side) by the operating shaft 84, the first traveling shift shaft 83 (the first traveling fork 83a). As a result, the first shift gear 51 is slid to the right (the other side), and the high-speed gear 51b of the first shift gear 51 meshes with the high-speed traveling gear 55 (the high-speed position of the first traveling transmission 50).
A ball detent mechanism 88 is provided on the upper part 10c of the transmission case 10, and the ball detent mechanism 88 moves the first traveling shift shaft 83 between the low speed and high speed positions and the low speed and high speed positions of the first traveling transmission 50. Held in neutral position.

As shown in FIGS. 7 and 9, the first traveling operation unit 85 (the first traveling shift shaft 83 (the first traveling fork 80a) and the operation shaft 84 (the arm 84a)) is connected to the first traveling transmission 50 in a side view. (The input shaft 21, the first travel transmission shaft 49, the first shift gear 51) and the steering shaft 74.
The operation shaft 84 is disposed in front of the input shaft 16a (the transmission shaft 19) of the hydrostatic continuously variable transmission 16 in a side view, and the traveling shift shaft 83 (the traveling fork 83a) and the operation shaft 84 (the arm 84a) are arranged. The transmission is arranged above the input shaft 16a (transmission shaft 19) of the hydrostatic continuously variable transmission 16.

[16]
Next, the shift lever 93 connected to the operation shaft 84 of the first traveling transmission 50 will be described.

  As shown in FIGS. 10, 11, 12, and 13, the transmission lever 93 is made of a round bar, and a channel-shaped connecting member 93a is connected to a lower portion of the transmission lever 93 by welding, and connected to the connecting member 93a. A hole 93b is opened. Similarly, a connection hole 84b is also opened above the operation shaft 84.

  With the above structure, as shown in FIGS. 10, 11, 12, and 13, the connecting member 93a of the shift lever 93 is mounted on the upper portion of the operating shaft 84, and the connecting hole 93b of the connecting member 93 of the shift lever 93 and the operating shaft 84 are formed. The transmission lever 93 is connected to the operation shaft 84 by connecting the bolt 94 to the connection hole 84b. The transmission lever 93 (operation shaft 84) and the clutch shaft 80 are located near the power steering mechanism 89 and the handle shaft 90, and the transmission lever 93 (operation shaft 84), the clutch shaft 80, and the handle shaft 90 are parallel to each other. It is in a state.

  As shown in FIGS. 10, 11, 12, and 13, a support member 96 made of a plate material is connected to an upper portion of the power steering mechanism 89, and a U-shaped notch 96a is formed at a rear portion of the support member 96. I have.

  As shown in FIGS. 12 and 13, in a state where the upper portion of the transmission lever 93 is inserted into the notch 96 a of the support member 96, as shown in FIG. The connecting member 93a of the transmission lever 93 is opened leftward (leftward and rightward) with respect to the notch 96a. With this structure, the direction of the notch 96a of the support member 96 and the direction of the connecting member 93a of the speed change lever 93 are orthogonal (cross) in a plan view.

  Thereby, as shown in FIG. 14, the notch 96a of the support member 96 supports the left and right inclination of the shift lever 93 with respect to the operation shaft 84. The forward / backward tilt of the speed change lever 93 with respect to the operation shaft 84 is supported by the connecting member 93 a of the speed change lever 93 and the bolt 94.

  As described in [15] above, when the first traveling transmission 50 is operated to the neutral position, as shown in FIG. 14, the direction of the notch 96 a of the support member 96 and the connection member of the transmission lever 93 are connected. The direction of 93a is orthogonal to the plane view. Thus, in a state where the first traveling transmission 50 is operated to the neutral position, the above-described cutout portion 96a of the support member 96, the connection member 93a of the transmission lever 93, and the support state of the transmission lever 93 by the bolt 94 are obtained.

  As described in [15] above, when the first traveling transmission 50 is operated to the low-speed position (high-speed position), the shift lever 93 is operated from the neutral position (see FIG. 14) to one side (the other side) by about 45 °. I do. Thus, even if the first traveling transmission 50 is operated to the low speed and high speed positions by the shift lever 93, the notch 96a of the support member 96, the connecting member 93a of the shift lever 93, and the bolt 94 of the shift lever 93 are used. A support state is obtained.

  As shown in FIGS. 9 and 13, by removing the shift lever lever 93 (the connecting member 93 a) and the bolt 94 from the operation shaft 84, the seal member 95 of the boss 10 k of the transmission case 10 is moved upward along the operation shaft 84. The sealing member 95 can be easily exchanged.

[17]
Next, an operation system of the first work transmission 32 will be described.

  As shown in FIG. 5, a first work shift shaft 100 is slidably supported in the left-right direction at a front portion of a right side portion 10 a of the transmission case 10, and a right portion of the first work shift shaft 100 is It protrudes outward (right side) from the right side part 10a. A first work fork 100a is connected to a left portion of the first work shift shaft 100, and the first work fork 100a extends rearward toward the first work transmission 32, and is connected to a right portion of the cylindrical member 31. Is engaged.

As shown in FIGS. 5, 10, and 12, a support portion 10n is provided outside the right side portion 10a of the transmission case 10. An operation lever 101 to which a triangular arm 101a is connected in a plan view is provided, and the arm 101a of the operation lever 101 is swingably supported around a vertical axis P3 of the support portion 10n. An arm 101 a is connected to the right side of the first work shift shaft 100.
As described above, the first work shift shaft 100 and the first work fork 100a of the first work shift shaft 100 constitute the first work operation unit 102 of the first work transmission 32.

  As shown in the previous section [3] and FIGS. 5 and 6, when the operation lever 101 is operated to the front side, the first work shift shaft 100 is slid to the right (the other side), and the cylindrical member 31 is moved to the right (the other side). By the sliding operation, the second gear 31b of the cylindrical member 31 meshes with the first working gear 30a on the left (one side) end of the plurality of first working gears 30 (the first working gear 32). High speed position H).

As shown in the preceding section [3] and FIGS. 5 and 6, when the operation lever 101 is operated to the rear side, the first work shift shaft 100 is slid to the left (one side), and the cylindrical member 31 is moved to the left (one side). , The first gear 31a of the cylindrical member 31 meshes with the first working gear 30b at the right (other side) end of the plurality of first working gears 30 (the first working transmission 32). Low speed position L).
A ball detent mechanism 103 is provided on the right side 10a of the transmission case 10, and the first work shift shaft 100 is moved by the ball detent mechanism 103 to the low and high speed positions L and H, and the low and high speed positions of the first work transmission 32. It is held at the neutral position between L and H.

As shown in FIGS. 5, 9, and 10, the first work operation unit 102 (the first work shift shaft 100 (the first work fork 100a)) has a first work transmission 32 (the input shaft 21 and the cylindrical shaft 28) in a side view. , The first work transmission shaft 23) and the steering shaft 74.
The first work operation unit 102 (the first work shift shaft 100 (the first work fork 100a)) is configured such that the input shaft 16a (the transmission shaft 19) of the hydrostatic continuously variable transmission 16 and the operation gear of the operation shaft 76 are viewed in side view. 76a.
The first traveling operation unit 85 (the first traveling shift shaft 83 (the first traveling fork 80a) and the operation shaft 84 (the arm 84a)) is connected to the first operation unit 102 (the first operation shift shaft 100 (the first traveling shift shaft 100)) in a side view. It is arranged above the working forks 100a)).

[18]
Next, an operation system of the second traveling transmission 57 will be described.

  As shown in FIG. 8, a second traveling shift shaft 104 is slidably supported in the left-right direction at a rear portion of a left side portion 10 b of the transmission case 10. It protrudes outward (left side) from the left side portion 10b. As shown in FIGS. 1 and 2, the shift lever 112 provided on the left lateral side of the driver's seat 111 and the left portion of the second travel shift shaft 104 serve as an operation arm 97 and a linkage mechanism (not shown). Connected through.

As shown in FIG. 8, a second traveling fork 104a is connected to a right portion of the second traveling shift shaft 104, and the second traveling fork 104a extends downward toward the second work transmission 57. The second shift gear 52 is engaged.
As described above, the second travel shift shaft 104 and the second travel fork 104a of the second travel shift shaft 104 constitute the second travel operation unit 105 of the second travel transmission 57.

  As shown in the preceding section [8] and FIGS. 4 and 8, when the second travel shift shaft 104 is slid to the left (one side) by the shift lever 112, the second travel shift shaft 104 (the second travel fork 104a). Thereby, the second shift gear 52 is slid to the left (one side), and the high-speed gear 52b of the second shift gear 51 is engaged with the high-speed traveling gear 55 (the high-speed position of the second traveling transmission 57).

As shown in the preceding section [8] and FIGS. 4 and 8, when the second travel shift shaft 104 is slid to the right (the other side) by the shift lever 112, the second travel shift shaft 104 (the second travel fork 104a). Accordingly, the second shift gear 52 is slid to the right (the other side), and the low-speed gear 52a of the second shift gear 52 is engaged with the low-speed traveling gear 53 (the low-speed position of the second traveling transmission 57).
A ball detent mechanism 106 is provided on the left side portion 10b of the transmission case 10, and the ball detent mechanism 106 moves the second traveling shift shaft 104 between the low and high speed positions and the low and high speed positions of the second traveling transmission 57. Held in neutral position.

  As shown in FIGS. 8, 9, and 12, the second traveling shift shaft 104 includes a second working transmission shaft 33, a planting transmission shaft 38 (bevel gear 40), and a second traveling transmission shaft 56 in side and rear views. And the rear wheel transmission shaft 59 (bevel gear 60).

[19]
Next, an operation system of the second work transmission 37 will be described.

As shown in the preceding section [4] and FIG. 5, an operation shaft 36 is slidably provided on the cylindrical portion 33a of the second work transmission shaft 33 and the right side 10a of the transmission case 10, and the right portion of the operation shaft 36 is provided. From the right side 10a of the transmission case 10 to the outside (right side).
As described above, the second operation unit 107 of the second operation transmission 37 is constituted by the operation shaft 36.

  As shown in FIGS. 5, 10, 11, and 12, a support member 108 bent in a U-shape when viewed from the front is connected to the right side 10a of the transmission case 10 to the outside. An operation lever 109 formed by bending a round bar is swingably supported around a vertical axis P4 of the support member 108, and a bifurcated arm 109a connected to the operation lever 109 is used as an operation shaft. 36 is connected to the right part.

With the above structure, the operating shaft 36 can be slid by operating the operating lever 109 around the axis P4. By sliding the operating shaft 36, the above-mentioned [4] and FIGS. As shown in FIG. 6, the second work transmission 37 is operated to the first to fourth speed positions 1F to 4F.
A ball detent mechanism 110 is provided on the right side 10a of the transmission case 10, and the operation shaft 36 is held by the ball detent mechanism 110 in the first to fourth speed positions 1F to 4F of the second work transmission 37.

[First Embodiment of the Invention]
In the above-mentioned [Embodiment for carrying out the invention], the structures provided inside and outside the hydrostatic continuously variable transmission 16 and the transmission case 10 may be arranged so that the right and left sides are reversed (the right and left are reversed). May be arranged).
With the configuration described above, the right side is one side (the hydrostatic continuously variable transmission 16 side), and the left side is the other side (the opposite side to the hydrostatic continuously variable transmission 16).

[Second Alternative Embodiment of the Invention]
In the above-mentioned [Embodiment of the Invention], the structure provided inside and outside the transmission case 10 is changed to the left and right while the hydrostatic stepless transmission 16 is provided on the left side portion 10b of the transmission case 16. They may be arranged in reverse (they may be arranged so as to be switched left and right).
With the above-described configuration, the right side is one side (the side opposite to the hydrostatic continuously variable transmission 16), and the left side is the other side (the hydrostatic continuously variable transmission 16 side).

[Third Alternative Embodiment of the Invention]
The first work transmission 32 shown in FIGS. 3, 4, 5, and 6 may be configured to be able to shift freely to three or four steps instead of two steps. The second work transmission 37 may be configured to be able to shift freely to three speeds, five speeds, and six speeds instead of four speeds.

[Fourth alternative embodiment of the invention]
The first traveling transmission 50 shown in FIGS. 3, 4, 7, and 8 may be configured so that the speed can be freely changed to three or four instead of two. The second traveling transmission 57 may be configured to be able to shift freely to three or four steps instead of two steps.

[Fifth Alternative Embodiment of the Invention]
The front wheel differential mechanism 73 shown in FIG. 9 is positioned directly above the virtual line K1 (the one in which the axis of the operation shaft 76 is extended upward (see the preceding item [11])) and the operation gear of the operation shaft 76 in a side view. 76a, and may be arranged in front of the imaginary line K1 in a side view and above the operation gear 76a of the operation shaft 76. Good. The second traveling transmission shaft 56 shown in FIG. 9 may be disposed directly above the front wheel differential mechanism 73 in a side view, or may be disposed above and in front of the front wheel differential mechanism 73 in a side view.

[Sixth Alternative Embodiment of the Invention]
The operation gear 76a of the operation shaft 76 shown in FIG. 9 may be configured as a sector gear (a semicircular shape having no rear portion).
With the above-described configuration, the front wheel differential mechanism 73 is located behind the imaginary line K1 (in which the axis of the operation shaft 76 is extended upward (see [11] in the previous section)) and the operation shaft. When the front wheel 1 is steered to the straight-ahead position in a state where the operation gear 76a is disposed above the operation gear 76a of 76, the operation gear 76a of the operation shaft 76 does not exist immediately below the front wheel differential mechanism 73 (operation A state in which the front wheel differential mechanism 73 is located immediately above a non-existing rear portion of the operating gear 76a of the shaft 76).

Next, when the operation gear 76a of the operation shaft 76 is rotated and the front wheel 1 is steered to the right (left), the right portion (left) of the operation gear 76a of the operation shaft 76 turns to the rear side. Then, the vehicle enters the lower side of the front wheel differential mechanism 73 in a side view, and the front wheel differential mechanism 73 is placed at a position above the operation gear 76a of the operation shaft 76 in a side view.
The input shaft 21, the first work transmission shaft 23, the reverse work clutch 27, the first travel transmission shaft 49, the first work transmission 32, and the first travel transmission 50 shown in FIG. It becomes the same state.

  In a state in which the operation gear 76a of the operation shaft 76 shown in FIG. 9 and the operation gear 76a of the operation shaft 76 are configured as fan-shaped gears as described above, the operation gear 76a of the operation shaft 76 is horizontally moved instead of being lowered backward. You may comprise so that it may be arrange | positioned.

[Seventh alternative embodiment of the invention]
As shown in FIG. 16, the low-speed portion of the high-speed shift range R1 of the two shift ranges R1 and R2 overlaps the high-speed portion of the low-speed shift range R2 of the two shift ranges R1 and R2. Thus, the speed ratio of the first work transmission device 32 at the high speed position H and the speed ratio of the low work position L are set, and the speed ratio of the second work transmission device 37 at the first speed position F1 and at the second speed position F2 are set. The gear ratio of the third speed position F3 and the gear ratio of the fourth speed position F4 may be set.

  In the state shown in FIG. 16, the third speed position FF3 of the first and second work transmissions 32 and 37 is located between the fifth speed and sixth speed positions FF5 and FF6 of the first and second work transmissions 32 and 37. Then, the fourth speed position FF4 of the first and second work transmissions 32, 37 is located between the sixth and seventh speed positions FF6, FF7 of the first and second work transmissions 32, 37.

  In this case, in the overlapping portion RR of the two shift ranges R1 and R2, the third speed position FF3 (speed ratio), the fourth speed position FF4 (speed ratio), and the fifth speed position of the first and second work transmissions 32 and 37 are provided. The speed ratio of the first working transmission 32 at the high speed position H and the speed ratio at the low speed position L of the first working transmission 32 are set so that the FF5 (speed ratio) and the sixth speed position FF6 (speed ratio) are different from each other (so as not to overlap). The gear ratio at the first speed position F1 of the second work transmission 37, the gear ratio at the second gear position F2, the gear ratio at the third gear position F3, and the gear ratio at the fourth gear position F4 are set.

In FIG. 16, the fourth speed position FF4 (speed ratio) of the first and second work transmissions 32 and 37 is the fifth speed and sixth speed position FF5 and FF6 (speed ratio) of the first and second work transmissions 32 and 37. ) May be arranged.
With this configuration, the overlapping portion RR of the two shift ranges R1 and R2 is smaller than the state shown in FIG.

  The present invention is applicable not only to a riding type rice transplanter but also to a riding type direct seeding machine having a direct sowing device as a working device.

DESCRIPTION OF SYMBOLS 1 Front wheel 2 Rear wheel 5 Work device 10 Transmission case 10a Right side of transmission case 10b Left side of transmission case 10d Front wall of transmission case 10f Bottom of transmission case 10p Rear wall of transmission case 14 Engine 16 Hydrostatic type stepless Transmission 21 Input shaft 23 Work transmission shaft 24 Large diameter gear 25 Shift member 27 Reverse work clutch 30 Work gear 30a Work gear at one end of a plurality of work gears 30b Other side of a plurality of work gears End working gear 31 Cylindrical member 31a Cylindrical member first gear 31b Cylindrical member second gear 32 Working transmission 49 Travel transmission shaft, first traveling transmission shaft 50 Travel transmission, first traveling transmission 51 First shift gear 52 second shift gear 53 traveling gear 54 traveling gear, first traveling transmission shaft Traveling gear at one end in the longitudinal direction of the vehicle 55 traveling gear, traveling gear corresponding to the highest speed position of the first and second traveling transmissions 56 second traveling transmission shaft 57 second traveling transmission 58 first bevel gear 59 Rear wheel transmission shaft 60 Second bevel gear 74 Steering shaft 74a Pinion gear of steering shaft 75 Steering handle 76 Operating shaft 76a Operating shaft operating gear 114 Small diameter gear K1 Virtual line

Claims (8)

Inside the transmission case, an input shaft to which power is transmitted, a work transmission shaft, a first traveling transmission shaft, a second traveling transmission shaft, and a front wheel transmission shaft are provided parallel to each other in the left-right direction.
A first traveling transmission is provided between a portion of the input shaft on one side in the longitudinal direction and a portion of the first traveling transmission shaft on one side in the longitudinal direction. Power is transmitted to the front and rear wheels,
A work transmission is provided between the other part of the input shaft in the longitudinal direction and the other part of the work transmission shaft in the longitudinal direction, and the power of the work transmission is provided on the body. Configured to be transmitted to the working device,
A first traveling transmission shaft provided with a second traveling transmission between a second portion of the second traveling transmission shaft in the longitudinal direction and a second portion of the second traveling transmission shaft in the longitudinal direction; Power of a transmission is transmitted to the rear wheels via the second traveling transmission,
A first transmission gear provided on the other side in the longitudinal direction of the second traveling transmission shaft, and a second transmission gear provided on the other side in the longitudinal direction of the front wheel differential mechanism are connected; The front wheel transmission shaft extends from a differential mechanism, and the power of the first traveling transmission is transmitted to the front wheels via the second traveling transmission and the front wheel differential mechanism,
Inside the transmission case, a steering shaft of a front wheel operated by a steering wheel is vertically arranged between the input shaft, the first traveling transmission, the work transmission and a front wall of the transmission case. And, a pinion gear is provided below the steering shaft,
On the bottom of the transmission case on the rear side of the pinion gear, an operation shaft for steering the front wheels is vertically arranged, and an operation gear is provided on an upper portion of the operation shaft,
By engaging the pinion gear and the operation gear, the operation of the steering handle is transmitted to the front wheels via the steering shaft and the operation shaft, and the front wheels are steered.
An operation shaft for performing a traveling operation of the first traveling transmission is connected to a traveling shift shaft via an arm, and the traveling shift shaft is coupled to the first traveling transmission via a traveling fork;
By setting an imaginary line extending the axis of the operation axis upward,
A side view of the input shaft, the first traveling transmission shaft, the work transmission shaft, the second traveling transmission shaft, the front wheel transmission shaft, the first traveling transmission, and the work transmission. Arranged between the virtual line and the rear wall of the mission case,
A paddy working machine wherein the arm and the traveling shift shaft are arranged between the virtual line and a front wall of the transmission case in a side view. The power of the input shaft is configured to be transmitted to the first traveling transmission shaft via the first traveling transmission, and the first traveling transmission shaft includes a small-diameter gear;
By providing a large-diameter gear on the work transmission shaft, by engaging the small-diameter gear and the large-diameter gear,
The power of the input shaft is configured to be transmitted to the first traveling transmission shaft, the small-diameter gear, the large-diameter gear, and the work transmission shaft,
The paddy working machine according to claim 1, wherein a plurality of work gears are fitted around the input shaft so as to be relatively rotatable, and the work transmission is provided between the work transmission shaft and the work gear.   The paddy working machine according to claim 2, further comprising a reverse working clutch that is operated in a transmission state during forward movement and is operated in a disconnected state during reverse movement between the large-diameter gear and the work transmission shaft. The reverse working clutch,
The work transmission shaft is provided with a shift member that can rotate and slide integrally with the shaft,
The transmission state is established by slidingly operating the shift member and engaging the large-diameter gear, and the cut-off state is established by sliding the shift member away from the large-diameter gear. Paddy field working machine according to the above. Wherein the first traveling transmission is
A first shift gear integrally rotatably and slidably supported by the input shaft; and a plurality of traveling gears fixed to the first traveling power transmission shaft, wherein the first shift gear is formed of the plurality of traveling gears. It is configured to bite into one,
The second travel transmission includes a second shift gear integrally rotatably and slidably supported on the second travel transmission shaft, and the plurality of travel gears. It is configured to bite into one of them,
The running gear corresponding to the highest speed position of the first and second running transmissions among the plurality of running gears is provided at a central portion of the first running transmission shaft in the longitudinal direction. The paddy working machine according to any one of 2 to 4. A first bevel gear is provided on the second traveling transmission shaft toward the second shift gear so that the first traveling transmission shaft is located outside the traveling gear at one end in a longitudinal direction of the first traveling transmission shaft,
6. A rear wheel transmission shaft for transmitting power to a rear wheel is disposed so as to be orthogonal to the second traveling transmission shaft, and a second bevel gear of the rear wheel transmission shaft is meshed with the first bevel gear. Paddy working machine as described. The work transmission,
A first gear and a second gear are provided on the cylindrical member so as to be rotatable integrally, and the cylindrical member is externally fitted to the work transmission shaft so as to be integrally rotatable and slidable;
Sliding the cylindrical member to one side to engage the first gear with the working gear at the other end of the plurality of working gears, sliding the cylindrical member to the other side, The second gear is engaged with a working gear at one end of the plurality of working gears to perform a shift,
The working gear at one end of the plurality of working gears has the smallest diameter among the plurality of working gears, and the working gear at the other end of the plurality of working gears is The paddy working machine according to any one of claims 2 to 6, which has a maximum diameter among a plurality of working gears. On the right or left side of the transmission case, a hydrostatic stepless transmission is provided,
The power of the engine is transmitted to the hydrostatic continuously variable transmission, and the power of the hydrostatic continuously variable transmission is transmitted to the input shaft,
One side in the longitudinal direction of the input shaft, one side in the longitudinal direction of the first traveling transmission shaft, and one side in the longitudinal direction of the work transmission shaft are the hydrostatic continuously variable transmission side,
The other side in the longitudinal direction of the input shaft, the other side in the longitudinal direction of the first traveling transmission shaft, and the other side in the longitudinal direction of the work transmission shaft are opposite to the hydrostatic continuously variable transmission. The paddy field working machine according to any one of claims 2 to 7.

Images