CN106385895B - Paddy field working machine - Google Patents

Abstract

The paddy field working machine of the present invention is characterized in that a travel transmission device is provided between a portion on one side in the longitudinal direction of an input shaft (21) and a portion on one side in the longitudinal direction of a travel transmission shaft (49). A work transmission device is provided between the other side portion of the input shaft (21) in the longitudinal direction and the other side portion of the work transmission shaft (23) in the longitudinal direction. A steering shaft (74) for the front wheels is disposed in the vertical direction between the front wall (10d) of the transmission (10) and the input shaft (21), the travel transmission device, and the work transmission device. The input shaft (21), the travel transmission shaft (49), the work transmission shaft (23), the travel transmission device, and the work transmission device are arranged between a virtual line (K1) and a rear wall portion (10p) of the transmission (10) when viewed from the side, the virtual line (K1) extends upward from the axial center of the operation shaft (76), and the operation shaft (76) steers the front wheels.

Description

Paddy field working machine

Technical Field

The present invention relates to a structure of a transmission system of a front wheel, a transmission system of a rear wheel, and a transmission system of a working device of a paddy field working machine having a seedling planting device or a direct seeding device as a working device.

Background

As described in patent document 1, a riding rice transplanter, which is an example of a paddy field working machine, has a transmission case at a front portion of a machine body, and a travel transmission device for transmitting power to front wheels and rear wheels and a working transmission device for transmitting power to a working device are provided inside the transmission case.

(Prior art document)

(patent document)

Patent document 1: japanese patent application laid-open publication No. 2011- "

Disclosure of Invention

(problems to be solved by the invention)

As a paddy field working machine, for example, there is a paddy field working machine having a steering mechanism of front wheels (a steering shaft operated by a steering handle, a planetary gear included in the steering shaft, an operation shaft coupled to the front wheels, an operation gear included in the operation shaft, and the like) inside a transmission case.

The invention aims to provide a paddy field working machine, which can properly arrange a steering mechanism of a front wheel, a running speed change device and a working speed change device in a gearbox.

(means for solving the problems)

[I]

The paddy field working machine of the present invention is characterized in that an input shaft, a working transmission shaft and a traveling transmission shaft are provided inside a transmission case, power is transmitted to the input shaft, the working transmission shaft and the traveling transmission shaft are parallel to each other in the left-right direction,

a running transmission device having power transmitted to front and rear wheels between a portion on one side in a longitudinal direction of the input shaft and a portion on one side in the longitudinal direction of the running transmission shaft,

a work transmission device is provided between the other side portion in the longitudinal direction of the input shaft and the other side portion in the longitudinal direction of the work transmission shaft, and the power of the work transmission device is transmitted to a work device provided in the machine body,

a steering shaft of front wheels is disposed in the transmission case in a vertical direction between a front wall portion of the transmission case and the input shaft, the traveling transmission device, and the work transmission device, the steering shaft being operated by a steering handle, and a planetary gear is provided at a lower portion of the steering shaft,

an operation shaft for steering the front wheels is disposed in the vertical direction at a portion of the bottom of the transmission case located on the rear side of the planetary gear, and an operation gear is provided on the upper portion of the operation shaft,

by engaging the planetary gear with the operating gear, the operation of the steering handle is transmitted to the front wheels via the steering shaft and the operating shaft, steering operation is performed on the front wheels,

a virtual line extending upward from the axis of the operating shaft is set,

the input shaft, the travel transmission shaft, the work transmission shaft, the travel transmission device, and the work transmission device are disposed between the virtual line and a rear wall portion of the transmission case when viewed from a side.

According to this configuration, when the operation shaft for steering the front wheels is provided at the bottom of the transmission case, the input shaft, the travel transmission shaft, the work transmission shaft, the travel transmission device, and the work transmission device are disposed so as to be located between a virtual line extending upward from the axial center of the operation shaft and the rear wall portion of the transmission case when viewed from the side, whereby the input shaft, the travel transmission shaft, the work transmission shaft, the travel transmission device, and the work transmission device are disposed at the rear half portion of the inside of the transmission case.

This allows a steering mechanism (steering shaft) for the front wheels to be smoothly and appropriately disposed in the front half portion of the interior of the transmission. Further, the transmission case does not need to be enlarged to dispose a steering mechanism (steering shaft) for the front wheels, and the entire transmission case can be reduced in size and weight.

According to this configuration, since the traveling transmission device is provided on one side and the working transmission device is provided on the other side in the left-right direction inside the transmission case, the traveling transmission device and the working transmission device can be smoothly arranged in the rear half of the inside of the transmission case.

[II]

In the above configuration, preferably, the power of the input shaft is transmitted to the travel transmission shaft via the travel transmission device, the travel transmission shaft has a small-diameter gear, the work transmission shaft has a large-diameter gear, and by engaging the small-diameter gear with the large-diameter gear,

the power of the input shaft is transmitted to the running transmission shaft, the small-caliber gear, the large-caliber gear and the operation transmission shaft,

the plurality of working gears are externally fitted to the input shaft so as to be relatively rotatable, and the working transmission device is configured from the working drive shaft to the working gears.

In general, in a transmission, since high-speed power is transmitted to an input shaft, it is necessary to sufficiently decelerate the power of the input shaft and transmit the decelerated power to a working transmission.

According to this configuration, the power of the input shaft is transmitted to the travel transmission shaft via the travel transmission device, and the power transmitted from the small-diameter gear of the travel transmission shaft to the large-diameter gear of the work transmission shaft is sufficiently reduced, so that a more appropriate gear ratio can be easily set for the sufficiently reduced power by the work transmission device.

According to this configuration, when the working transmission device is configured, the working transmission device is configured in a small space from the working drive shaft to the working gear (input shaft), and therefore the working transmission device can be downsized, and the entire transmission system from the input shaft to the working device can be downsized.

[III]

In the above configuration, it is preferable that a reverse operation clutch is provided between the large diameter gear and the operation transmission shaft, and the reverse operation clutch is operated to a transmission state when the machine body moves forward and is operated to a cut-off state when the machine body moves backward.

Since the paddy field working machine cannot perform work while moving backward, it is necessary to stop the working device when the machine body moves backward.

According to this configuration, the reverse operation clutch is provided in the large diameter gear of the operation drive shaft, the power of the small diameter gear of the travel drive shaft is transmitted to the large diameter gear of the operation drive shaft, and the reverse operation clutch is operated to a disconnected state when the machine body is retracted, whereby the power can be disconnected at a position close to the input shaft, that is, at a position on the rear side of the travel drive shaft, and the operation device can be appropriately stopped.

[IV]

In the above configuration, preferably, the reverse operation clutch includes a displacement member that rotates integrally with the operation transmission shaft and is free to slide,

the shift member is slidably operated to engage the shift member with the large-diameter gear to form a transmission state, and the shift member is slidably operated to disengage the shift member from the large-diameter gear to form a cut-off state.

According to this configuration, the reverse operation clutch can be configured by sliding operation of the displacement member (engagement and disengagement of the displacement member with and from the large diameter gear), and the reverse operation clutch can be configured simply.

[V]

In the above-described configuration, preferably, the paddy field working machine has a second travel transmission shaft in the left-right direction, the second travel transmission shaft being parallel to the first travel transmission shaft as the travel transmission shaft,

in addition to the first running gear change mechanism as the running gear change mechanism, a second running gear change mechanism is provided between a portion on the other side in the longitudinal direction of the first running transmission shaft and a portion on the other side in the longitudinal direction of the second running transmission shaft,

the power of the first running transmission is transmitted to the front wheels and the rear wheels via the second running transmission.

According to this configuration, as described in [ I ], when the traveling transmission device (first traveling transmission device) is provided on one side and the work transmission device is provided on the other side in the left-right direction inside the transmission case, the second traveling transmission device is further provided on the other side.

In this way, the first traveling transmission device, the second traveling transmission device, and the work transmission device can be smoothly arranged in the rear half of the interior of the transmission case, and therefore, in this respect, it is not necessary to increase the size of the transmission case, and it is possible to achieve a reduction in size and weight of the entire transmission case.

[VI]

In the above-described configuration, it is preferable that the first travel speed change device includes a first shift gear supported on the input shaft so as to be rotatable and slidable integrally, and a plurality of travel gears fixed to the first travel transmission shaft such that the first shift gear meshes with one of the plurality of travel gears,

the second running transmission device has a second shift gear and a plurality of running gears, the second shift gear being supported on the second running transmission shaft in an integrally revolving and freely sliding manner so as to mesh with one of the plurality of running gears,

among the plurality of running gears, a running gear corresponding to the highest speed position of the first running transmission and the second running transmission is located at a portion on the center side in the longitudinal direction of the first running propeller shaft.

According to this configuration, the first travel speed change device performs speed change by engaging the first shift gear with the travel gear of the first travel transmission shaft, and the second travel speed change device performs speed change by engaging the second shift gear with the travel gear of the first travel transmission shaft, the travel gear of the first travel transmission shaft being a common member of the first travel speed change device and the second travel speed change device.

According to this configuration, since the running gear corresponding to the highest speed position of the first running transmission and the second running transmission is located at the central portion in the longitudinal direction of the first running propeller shaft, the highest speed of the first running transmission and the second running transmission can be obtained by engaging the first shift gear with the running gear corresponding to the highest speed position of the first running transmission and engaging the second shift gear with the same running gear corresponding to the highest speed position of the first running transmission.

In this case, the first shift gear, the second shift gear, and the running gear corresponding to the highest speed positions of the first running transmission and the second running transmission are aligned in a row at the center portion in the longitudinal direction of the input shaft, the first running transmission, and the second running transmission.

[VII]

In the above configuration, it is preferable that the second travel transmission shaft includes a first bevel gear facing the second shift gear, the first bevel gear is located on an outer side of the travel gear on one end portion in a longitudinal direction of the first travel transmission shaft,

a rear wheel transmission shaft for transmitting power to the rear wheel is disposed perpendicularly to the second travel transmission shaft such that a second bevel gear of the rear wheel transmission shaft is engaged with the first bevel gear.

When the second travel transmission shaft has the second shift gear and the second travel transmission shaft has the first bevel gear, according to the seventh feature of the present invention, the first bevel gear is provided in the second travel transmission shaft and is located at a position that is further outward than the travel gear at the end portion on one side in the longitudinal direction of the first travel transmission shaft, whereby the first bevel gear can be smoothly arranged on the second travel transmission shaft while avoiding interference of the first bevel gear with the travel gear and the second shift gear.

Further, in the paddy field working machine having the rear wheel drive shaft for transmitting power to the rear wheel, and the second bevel gear of the rear wheel drive shaft being meshed with the first bevel gear, according to the above configuration, since the first bevel gear (the gear teeth of the first bevel gear) is disposed on the second travel drive shaft so as to face the second shift gear, the second bevel gear is positioned between the first bevel gear and the second shift gear, and the second bevel gear facing the travel gear can be smoothly disposed.

[VIII]

In the above-described configuration, preferably, the work transmission device has a first gear and a second gear that are integrally rotatable, on a cylindrical member externally fitted to the work transmission shaft so as to be integrally rotatable and slidably operable,

the work transmission device shifts gears by a manner in which

Sliding the cylindrical member to one side to cause the first gear to mesh with an end portion of the plurality of working gears located on the other side; and

sliding the cylindrical member toward the other side to cause the second gear to mesh with the working gear located at one end portion of the plurality of working gears,

the work gear located at one end of the plurality of work gears has the smallest diameter among the plurality of work gears, and the work gear located at the other end of the plurality of work gears has the largest diameter among the plurality of work gears.

According to this configuration, since the second gear is located at the center of the work propeller shaft in the longitudinal direction and the first gear is located at the other end of the work propeller shaft in the longitudinal direction, the first gear is close to the bearing at the other end of the work propeller shaft in the longitudinal direction.

According to this configuration, the diameter of the second gear that meshes with the working gear located at the one end portion is maximized, and the diameter of the first gear that meshes with the working gear located at the other end portion is minimized, by setting the working gear located at the one end portion to be the smallest diameter and the working gear located at the other end portion to be the largest diameter, for the plurality of working gears of the working transmission.

In this way, even if the first gear is close to the bearing at the other end portion in the longitudinal direction of the work transmission shaft, interference between the first gear and the bearing at the other end portion in the longitudinal direction of the work transmission shaft can be smoothly avoided by making the diameter of the first gear small.

[IX]

In the above configuration, preferably, a hydrostatic continuously variable transmission is provided on a right side portion or a left side portion of the transmission,

power of an engine is transmitted to the hydrostatic continuously variable transmission, power of the hydrostatic continuously variable transmission is transmitted to the input shaft,

one side in the long side direction of the input shaft, one side in the long side direction of the travel transmission shaft, and one side in the long side direction of the work transmission shaft are the hydrostatic continuously variable transmission side,

the other side in the long side direction of the input shaft, the other side in the long side direction of the travel transmission shaft, and the other side in the long side direction of the work transmission shaft are the sides opposite to the hydrostatic continuously variable transmission.

According to this configuration, when the hydrostatic continuously variable transmission is provided in the right side portion (left side portion) of the transmission, a portion of the traveling transmission on the right side (left side) (a portion on the hydrostatic continuously variable transmission side) and a portion of the working transmission on the left side (right side) (a portion on the opposite side from the hydrostatic continuously variable transmission) are provided in the transmission.

This makes it possible to balance the hydrostatic continuously variable transmission and the transmission (the traveling transmission and the work transmission) in the right-left direction.

Drawings

Fig. 1 is an overall side view of the left side of a riding rice transplanter.

Fig. 2 is an overall plan view of the riding type rice transplanter.

Fig. 3 is a schematic view showing a transmission system of the front and rear wheels and a transmission system of the seedling planting device.

Fig. 4 is a cross-sectional top view of a transmission case of a transmission system showing front and rear wheels.

Fig. 5 is a cross-sectional top view showing a transmission of a transmission system of the seedling planting device.

Fig. 6 is a cross-sectional top view of the vicinity of the first and second work transmissions in the transmission.

Fig. 7 is a cross-sectional top view of the vicinity of the first and second running gears in the transmission.

Fig. 8 is a cross-sectional top view near a rear wheel propeller shaft in the transmission.

Fig. 9 is a longitudinal sectional side view of the right side in the transmission.

Fig. 10 is a right side view of the transmission.

FIG. 11 is a rear view of the transmission.

Fig. 12 is a perspective view of the transmission.

Fig. 13 is a perspective view of the vicinity of the power steering mechanism in the transmission.

Fig. 14 is a cross-sectional plan view of the notch portion of the support member and the vicinity of the link member of the shift lever.

Fig. 15 is a schematic diagram showing the entire shift ranges of the first and second work transmission devices.

Fig. 16 is a schematic diagram showing the entire shift ranges of the first and second work transmission devices in a seventh other embodiment of the present invention.

Description of the reference numerals

1: front wheel

2: rear wheel

5: working device

10: gear box

10 a: right side part of gearbox

10 b: left side of the gearbox

10 d: front wall part of gearbox

10 f: bottom of the gearbox

10 p: rear wall part of gearbox

14: engine

16: hydrostatic stepless speed change device

21: input shaft

23: operation transmission shaft

24: large-diameter gear

25: displacement member

27: back-off operation clutch

30: working gear

30 a: one end part of the plurality of operation gears

30 b: a working gear located at the other end of the plurality of working gears

31: cylinder part

31 a: first gear of cylindrical component

31 b: second gear of cylindrical component

32: operation speed changing device

49: driving transmission shaft and first driving transmission shaft

50: travel speed change device and first travel speed change device

51: first shift gear

52: second shift gear

53: running gear

54: running gear, running gear of one end portion in long side direction of first running transmission shaft

55: running gear, running gear corresponding to the highest speed position of the first running gear and the second running gear

56: second driving transmission shaft

57: second running speed change device

58: first bevel gear

59: rear wheel transmission shaft

60: second bevel gear

74: steering shaft

74 a: planetary gear of steering shaft

75: operating handle

76: operating shaft

76 a: operating gear of operating shaft

114: small-bore gear

K1: virtual line

Detailed Description

In fig. 1, 2, 4, 5, and 9 to 12, F denotes "front" of the body, "B" rear "of the body," U "upper" of the body, and D "lower" of the body. In a state of being directed to the front of the body, R represents the "right" of the body, and L represents the "left" of the body.

(1)

The following describes an outline of the entirety of a riding rice transplanter as an example of a paddy field working machine.

As shown in fig. 1 and 2, a link mechanism 3 is provided at the rear of the machine body supported by the left and right front wheels 1 and the left and right rear wheels 2 so as to be vertically swingable. An 8-row planting type seedling planting device 5 (corresponding to a working device) is supported at the rear part of the link mechanism 3 so as to freely swing around the front and rear axis. The riding type rice transplanter also comprises a hydraulic cylinder 4, and the hydraulic cylinder 4 drives the link mechanism 3 to lift.

As shown in fig. 1 and 2, the seedling planting device 5 includes 4 transmission boxes 6, a pair of revolving boxes 7 supported at the rear of the transmission boxes 6 in a freely revolving driving manner, a pair of planting arms 8 provided at both ends of the revolving boxes 7, a ground contact floating plate 9, a seedling carrying table 113, and the like.

Thus, the seedling stage 113 is driven to reciprocate horizontally in the right-left direction, the rotating box 7 is driven to rotate, and the transplanting arms 8 alternately take out seedlings from the lower part of the seedling stage 113 and transplant the seedlings into the farmland.

As shown in fig. 1, a transmission case 10 is provided at the front of the machine body, a right (left) front axle box 11 is connected to the rear of a right side portion 10a (left side portion 10b) of the transmission case 10, the right (left) front axle box 11 extends outward, and the right (left) front wheel 1 is supported at the end of the right (left) front axle box 11 so as to be steerable. A rear axle box 12 is supported at the rear of the machine body, and a right (left) rear wheel 2 is supported at the right (left) end of the rear axle box 12.

As shown in fig. 1, a support frame 13 is coupled to a front portion of the transmission case 10 and extends to a front side, an engine 14 is supported by the support frame 13, and a hood 15 covers the engine 14.

As shown in fig. 1, 3, and 4, a hydrostatic continuously variable transmission 16 is connected to a front portion of the left side portion 10b of the transmission 10. A belt 17 is attached to the outside of the transmission 10 across 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 is transmitted to the hydrostatic continuously variable transmission 16 via the belt 17.

(2)

The power of the engine 14 is transmitted to the seedling planting device 5 via the hydrostatic continuously variable transmission 16, the first working transmission 32, the second working transmission 37, and the planting transmission shaft 38.

Next, a description will be given of a portion from the input shaft 21 to the reverse operation clutch 27 and the first operation transmission shaft 23 (corresponding to the operation transmission shaft) inside the transmission case 10 with respect to the transmission system of the seedling planting device 5.

As shown in fig. 3 and 4, the input shaft 16a and the output shaft 16b of the hydrostatic continuously variable transmission 16 are arranged in the left-right direction and enter the transmission 10, and the hydraulic pump 18 is coupled to the front of the right side portion 10a of the transmission 10. Inside the transmission 10, a propeller shaft 19 is coupled to a hydrostatic continuously variable transmission 16 via an input shaft 16a and an input shaft 18a of a hydraulic pump 18 via a cylindrical coupling member 20.

The hydraulic pump 18 supplies the hydraulic oil to the power steering mechanism 89 (see (11) below) and the hydraulic cylinder 4, and supplies (charge) the hydraulic oil to the hydrostatic continuously variable transmission 16. As shown in fig. 9, the lower portion of the inner surface of the left side portion 10b of the transmission case 10 has a suction port 10m, and the lubricating oil of the transmission case 10 is supplied as the hydraulic oil from the suction port 10m of the transmission case 10 to the hydraulic pump 18.

As shown in fig. 3, 4, 5, and 9, in the transmission case 10, the input shaft 21 is supported in the left-right direction in the vicinity of the center in the front-rear direction directly below the upper portion 10c of the transmission case 10 when viewed from the side, and the output shaft 16b of the hydrostatic continuously variable transmission device 16 and the input shaft 21 are connected to each other via a cylindrical connecting member 22.

As shown in fig. 3, 5, and 9, the first work transmission shaft 23 is supported at a position slightly below the front side of the input shaft 21 in parallel with the input shaft 21 in the left-right direction when viewed from the side. A large-diameter gear 24 having a sufficiently large diameter is fitted around a portion on the left side (one side) in the longitudinal direction of the first working transmission shaft 23 in a relatively freely rotatable manner.

As shown in fig. 3, 4, and (7) below, the power of the input shaft 21 is transmitted to the first travel transmission shaft 49 via the first travel transmission device 50, and a small-diameter gear 114 is coupled to a portion on the left side (one side) in the longitudinal direction of the first travel transmission shaft 49. The large diameter gear 24 and the small diameter gear 114 are engaged.

As shown in fig. 3, 5 and 9, the displacement member 25 is externally fitted to the first working transmission shaft 23 in a manner of rotating integrally and operating freely slidably through a spline structure, and the spring 26 urges the displacement member 25 to the large diameter gear 24.

As described above, the rearward working clutch 27 is formed between the large diameter gear 24 and the displacement member 25 (between the large diameter gear 24 and the first working transmission shaft 23) by the displacement member 25 at the left side (one side) in the longitudinal direction of the first working transmission shaft 23.

As shown in fig. 3 and 5, when the shifting member 25 is slid to the right side to engage the shifting member 25 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 operation transmission shaft 23 via the first travel transmission device 50, the first travel transmission shaft 49, the small diameter gear 114, the large diameter gear 24, and the shifting member 25. When the displacement member 25 is operated to the left side to separate the displacement member 25 from the large diameter gear 24 (the disengaged state of the reverse operation clutch 27), the power of the input shaft 21 is disengaged between the large diameter gear 24 and the displacement member 25 (between the large diameter gear 24 and the first operation transmission shaft 23).

At this time, as described in (14) below, the reverse operation clutch 27 is operated to the transmission state when moving forward, and is operated to the cut-off state when moving backward.

According to the above configuration, as shown in fig. 3 and 5, the power of the engine 14 is transmitted to the first working transmission shaft 23 via the hydrostatic continuously variable transmission device 16, the input shaft 21, the first traveling transmission device 50, the first traveling transmission shaft 49, the small-diameter gear 114, the large-diameter gear 24, and the reverse working clutch 27.

(3)

Next, a description will be given of a portion from the first operation transmission shaft 23 to the first operation speed changing device 32 (corresponding to an operation speed changing device) inside the transmission case 10 with respect to the transmission system of the seedling planting device 5.

As shown in fig. 3, 5, and 6, the cylindrical shaft 28 is fitted to the right (other) portion of the input shaft 21 in the longitudinal direction thereof via a bearing 29 so as to be relatively rotatable (the inner surface of the cylindrical shaft 28 does not contact the outer surface of the input shaft 21), and a plurality of (5) first working gears 30 (corresponding to working gears) are fitted to the cylindrical shaft 28 and supported. The plurality of first operation gears 30 are connected to each other so as to rotate integrally, and the plurality of first operation gears 30 are externally fitted to and connected to the cylindrical shaft 28.

At this time, as shown in fig. 6, the cylindrical bearing sleeve 28a of the cylindrical shaft 28 to which the bearing 29 is attached has an outer diameter D1 of the bearing sleeve 28a of the cylindrical shaft 28 larger than an inner diameter D2 of the first work gear 30 (outer diameter of the cylindrical shaft 28).

As shown in fig. 5 and 9, when viewed in the direction of the input shaft 21 and the first work transmission shaft 23 (when viewed from the side), the outer peripheral portion of the large diameter gear 24 overlaps the outer peripheral portion of the first work gear 30.

As shown in fig. 3, 5, and 6, a cylindrical member 31 is fitted around the first work transmission shaft 23 at a portion on the right side (the other side) in the longitudinal direction of the first work transmission shaft 23 in a manner of turning integrally and operating freely slidably by means of a spline structure. The cylindrical member 31 has a first gear 31a with a small diameter at a right side (the other side) in the longitudinal direction thereof, and a second gear 31b with a large diameter at a left side (the one side) in the longitudinal direction thereof.

In the state shown in fig. 3, 5, and 6, the cylinder member 31 is slid to the right (the other side) so that the second gear 31b of the cylinder member 31 meshes with the first working gear 30a located at the end portion on the left (one side) among the plurality of first working gears 30 (the high speed position H of the first working transmission device 32).

When the cylindrical member 31 in the state shown in fig. 3, 5, and 6 is slid to the left (one side), the first gear 31a of the cylindrical member 31 meshes with the first working gear 30b located at the end portion on the right (other side) among the plurality of first working gears 30 (the low speed position L of the first working speed changing device 32).

As shown in fig. 6, the length L1 of the cylindrical member 31 (from the first gear 31a to the second gear 31b) is slightly longer than the length L2 of the line of the first work gears 30 (from the first work gear 30a at the end on the left side (one side) to the first work gear 30b at the end on the right side (the other side)) of the line of the plurality of first work gears 30 aligned in the longitudinal direction of the input shaft 21.

As described above, as shown in fig. 3, 5, and 6, the first work transmission device 32, which freely performs 2-step speed change, is configured by the cylindrical member 31 (the first gear 31a and the second gear 31b) and the first work gears 30(30a, 30b) between the portion on the right side (the other side) in the longitudinal direction of the input shaft 21 (the cylindrical shaft 28) and the portion on the right side (the other side) in the longitudinal direction of the first work transmission shaft 23.

As shown in fig. 3, 5, and 6, among the plurality of first work gears 30, the first work gear 30a positioned at the end portion on the left side (one side) among the plurality of first work gears 30 has the smallest diameter, and the first work gear 30b positioned at the end portion on the right side (the other side) among the plurality of first work gears 30 has the largest diameter. The first gear 31a of the cylindrical member 31 has a small diameter, and the second gear 31b of the cylindrical member 31 has a large diameter.

Thus, as shown in fig. 6, when the cylindrical member 31 is slid to the right (the other side) and the second gear 31b of the cylindrical member 31 is engaged with the first working gear 30a positioned at the end portion on the left (the one side) among the plurality of first working gears 30 (the high speed position H of the first working transmission device 32), the first gear 31a of the cylindrical member 31 does not contact the bearing sleeve 10e of the bearing 98 of the input shaft 21 in the transmission case 10.

With the above configuration, as shown in fig. 3, 5, and 6, the power of the first work transmission shaft 23 is transmitted to the first work transmission device 32 (the cylindrical member 31 (the first gear 31a and the second gear 31b), the first work gear 30(30a, 30b), and the cylindrical shaft 28) to perform 2-step speed change.

(4)

Next, a description will be given of a portion from the first operation speed changing device 32 to the second operation speed changing device 37 inside the transmission case 10 with respect to the seedling planting device 5.

As shown in fig. 3, 5, and 9, the second work transmission shaft 33 is supported directly below the upper side portion 10c of the transmission case 10 in the left-right direction in parallel with the input shaft 21 and the first work transmission shaft 23 and is located on the rear side of the input shaft 21 when viewed from the side.

As shown in fig. 3, 5, and 6, a cylindrical portion 33a is formed in a portion on the right side (the other side) in the longitudinal direction of the second work transmission shaft 33, and a plurality of (4) second work gears 34 are fitted over the cylindrical portion 33a of the second work transmission shaft 33 so as to be relatively rotatable. Each of the first work gears 30 (except for the first work gear 30b located at the end portion on the right side (the other side) among the plurality of first work gears 30) is engaged with each of the second work gears 34, respectively.

As shown in fig. 6, a hole opening in the radial direction is formed in a portion of the cylindrical portion 33a of the second work transmission shaft 33 corresponding to the second work gear 34, and a spherical member 35 that is movable in the radial direction is provided in the hole. The cylindrical portion 33a of the second work transmission shaft 33 has an operating shaft 36 that is slidable, and the distal end portion of the operating shaft 36 has a large-diameter portion 36 a.

As shown in fig. 6, when the spherical member 35 is pushed radially outward by the large diameter portion 36a of the operating shaft 36, the spherical member 35 is positioned so as to straddle the cylindrical portion 33a of the second work transmission shaft 33 and the second work gear 34, and the second work gear 34 is coupled to the cylindrical portion 33a of the second work transmission shaft 33.

As shown in fig. 6, in a portion other than the large diameter portion 36a of the operation shaft 36, the spherical member 35 is displaced from the second operation gear 34 toward the center side in the radial direction so that the second operation gear 34 is not coupled to the cylindrical portion 33a of the second operation transmission shaft 33.

By sliding the operation shaft 36 as described above, power is transmitted from the first operation gear 30 to the second operation transmission shaft 33 via the second operation gear 34 coupled to the cylindrical portion 33a of the second operation transmission shaft 33.

As described above, as shown in fig. 3, 5, and 6, the second work transmission device 37, which is freely shifted in 4 steps, is configured by the first work gear 30 and the second work gear 34 between the portion (the cylindrical shaft 28) on the right side (the other side) in the longitudinal direction of the input shaft 21 and the portion on the right side (the other side) in the longitudinal direction of the second work transmission shaft 33.

As shown in fig. 6, the second work transmission device 37 is in the 1-speed position F1 in a state in which the second work gear 34 located at the end portion on the right side (the other side) among the plurality of second work gears 34 is coupled to the cylindrical portion 33a of the second work transmission shaft 33.

The state in which the second working gear 34, which is arranged second from the end on the right side (the other side) among the plurality of second working gears 34, is coupled to the cylindrical shaft 33a of the second working transmission shaft 33 is the 2-speed position F2.

The state in which the second working gear 34, which is arranged at the third position from the end portion on the right side (the other side) among the plurality of second working gears 34, is coupled to the cylindrical shaft 33a of the second working power shaft 33 is the 3-speed position F3.

The state in which the second working gear 34 arranged fourth from the end on the right side (the other side) among the plurality of second working gears 34 is coupled to the cylindrical shaft 33a of the second working transmission shaft 33 is the 4-speed position F4.

The 1-speed position F1 is the highest speed position, the 2-speed position F2 is the lowest speed position than the 1-speed position F1, the 3-speed position F3 is the lowest speed position than the 2-speed position F2, and the 4-speed position F4 is the lowest speed position.

According to the above configuration, as shown in fig. 3, 5 and 6, the power of the first work transmission device 32 is transmitted to the second work transmission device 37 (the first work gear 30 and the second work gear 34), and 4-stage speed change is performed, and further, the power is transmitted to the second work transmission shaft 33.

(5)

Next, the section from the second operation speed changing device 37 to the seedling planting device 5 will be explained with respect to the transmission system of the seedling planting device 5.

As shown in fig. 3, 5 and 9, the implanting transmission shaft 38 is supported at an upper portion of a rear portion of the transmission case 10 in the front-rear direction, the height positions of the implanting transmission shaft 38 and the second working transmission shaft 33 are the same when viewed from the side, and the implanting transmission shaft 38 is disposed at the rear side of the second working transmission shaft 33. The insertion drive shaft 38 is disposed at the center CL in the left-right direction of the machine body when viewed from above, and is perpendicular to the second working drive shaft 33.

As shown in fig. 1, 10, and 11, left and right body frames 45 are coupled to the rear portion of the transmission case 10 and extend rearward, and the rear axle boxes 12 are supported by the rear portions of the left and right body frames 45. The insertion transmission shaft 38 is disposed between the left and right body frames 45 when viewed from above, and is disposed at the same height as the left and right body frames 45 so as to overlap the left and right body frames 45 when viewed from the side.

As shown in fig. 1, a transmission shaft (not shown) connected to the insertion transmission shaft 38 extends rearward from between the left and right body frames 45 when viewed from above, and extends rearward at a position overlapping with the left and right body frames 45 at the same height as the left and right body frames 45 when viewed from the side. A driving shaft 47 coupled to the rear portion of the driving shaft (not shown) extends to the rear side and is coupled to an input shaft (not shown) of the seedling planting device 5.

As shown in fig. 3, 5, and 9, a bevel gear 39 is connected to the left (one) end of the second work transmission shaft 33 in the longitudinal direction. The sleeve member 48 is fitted over the insertion drive shaft 38 in a freely rotatable manner, the bevel gear 40 is coupled to the sleeve member 48, and the bevel gear 39 is engaged with the bevel gear 40.

As shown in fig. 3, 5 and 9, the displacement member 41 is externally fitted to the insertion drive shaft 38 in a manner rotatable integrally and slidably by a spline structure, the spring 42 urges the displacement member 41 toward the bevel gear 40, the operation shaft 43 urges the displacement member 41 away from the bevel gear 40, and the operation arm 46 slidably operates the operation shaft 43.

As described above, the shift member 41 forms the insertion clutch 44 between the bevel gear 40 and the shift member 41.

As shown in fig. 3 and 5, when the operation shaft 43 is slidingly operated to the right side (the other side), the displacement member 41 is slidingly operated to the front side by the spring 42, and is engaged with the sleeve member 48 (the bevel gear 40) (the transmission state of the insertion clutch 44). Thereby, the power of the second working transmission shaft 33 is transmitted to the insertion transmission shaft 38 via the bevel gears 39, 40 and the sleeve member 48.

As shown in fig. 3 and 5, when the operating shaft 43 is operated to the left (one side), the displacement member 41 is displaced from the sleeve member 48 (bevel gear 40) by the operating shaft 43 (the cut-off state of the inserting clutch 44). Thereby, the power of the second working transmission shaft 33 is cut off between the displacement member 41 and the sleeve member 48 (bevel gear 40).

With the above configuration, as shown in fig. 1, 3 and 5, the power of the second working transmission shaft 33 is transmitted to the seedling planting device 5 via the planting clutch 44, the planting transmission shaft 38, the transmission shaft 47.

(6)

The overall shift ranges R1, R2 of the first and second operation speed changing devices 32, 37 will be explained with respect to the transmission system of the seedling planting device 5.

The speed of the power transmitted to the seedling planting device 5 determines the interval (planting distance) between the seedlings planted on the farmland surface by the planting arms 8 in the front-rear direction, and the faster the speed of the power transmitted to the seedling planting device 5, the faster the speed of the revolving box 7, the smaller (narrower) the planting distance of the revolving drive.

As described in (3) above, the first work transmission device 32 is free to perform the 2-stage shift between the high speed position H and the low speed position L, and as described in (4) above, the second work transmission device 37 is free to perform the 4-stage shift between the 1-speed position F1 to the 4-speed position F4, and therefore, the first work transmission device 32 and the second work transmission device 37 are free to perform the 8-stage shift.

At this time, as shown in FIGS. 6 and 15,

the state in which the first work transmission 32 is in the high position H and the second work transmission 37 is in the 1 position F1 is set to the 1 position FF1 for the first and second work transmissions 32, 37.

The state in which the first work transmission 32 is in the high position H and the second work transmission 37 is in the 2-speed position F2 is set to the 2-speed position FF2 of the first and second work transmissions 32, 37.

The state in which the first work transmission 32 is in the high position H and the second work transmission 37 is in the 3-speed position F3 is set to the 3-speed position FF3 of the first and second work transmissions 32, 37.

The state in which the first work transmission 32 is in the high position H and the second work transmission 37 is in the 4-speed position F4 is set to the 4-speed position FF4 of the first and second work transmissions 32, 37.

The state in which the first work transmission 32 is in the low-speed position L and the second work transmission 37 is in the 1-speed position F1 is set to the 5-speed position FF5 for the first and second work transmissions 32, 37.

The state with the first work transmission 32 in the low-speed position L and the second work transmission 37 in the 2-speed position F2 is set to the 6-speed position FF6 for the first and second work transmissions 32, 37.

The state with the first work transmission 32 in the low-speed position L and the second work transmission 37 in the 3-speed position F3 is set to the 7-speed position FF7 for the first and second work transmissions 32, 37.

The state with the first work transmission 32 in the low-speed position L and the second work transmission 37 in the 4-speed position F4 is set to the 8-speed position FF8 for the first and second work transmissions 32, 37.

As shown in fig. 15, the overall shift range of the 1-speed positions FF1 to FF4 of the first work speed change device 32 and the second work speed change device 37 is set to R1 (the overall shift range R1 of the first work speed change device 32 and the second work speed change device 37 when the second work speed change device 37 is operated to each shift position (1-speed position F1 to F4) in a state where the second gear 31b of the cylindrical member 31 in the first work speed change device 32 is meshed with the first work gear 30a located at one end of the plurality of first work gears 30).

As shown in fig. 15, the overall shift ranges of the 5-speed positions FF5 to FF8 of the first work speed change device 32 and the second work speed change device 37 are set to R2 (the overall shift ranges R2 of the first work speed change device 32 and the second work speed change device 37 when the second work speed change device 37 is operated to each shift position (1-speed position F1 to F4) in a state where the first gear 31a of the cylindrical member 31 in the first work speed change device 32 is meshed with the first work gear 30b located at the other end of the plurality of first work gears 30).

At this time, as shown in fig. 15, the 1-speed position FF1 of the first work speed changing device 32 and the second work speed changing device 37 is the highest speed position (the row pitch is smallest), the 2-, 3-, 4-, 5-, 6-, and 7-speed positions FF2 to FF7 of the first work speed changing device 32 and the second work speed changing device 37 are gradually reduced (the row pitch is gradually increased), and the 8-speed position FF8 of the first work speed changing device 32 and the second work speed changing device 37 is the lowest speed position (the row pitch is largest).

As shown in fig. 6 and 15, the gear ratio at the high speed position H and the gear ratio at the low speed position L of the first work transmission device 32 are set so that the 2 shift ranges R1, R2 are separated from each other without overlapping (the 4-speed position FF4 of the first work transmission device 32 and the second work transmission device 37 is higher than the 5-speed position FF5 of the first work transmission device 32 and the second work transmission device 37), and the gear ratio at the 1-speed position F1, the gear ratio at the 2-speed position F2, the gear ratio at the 3-speed position F3, and the gear ratio at the 4-speed position F4 of the second work transmission device 37 are set.

(7)

The power of the engine 14 is transmitted from the hydrostatic continuously variable transmission device 16, the first running transmission device 50, and the second running transmission device 57 to the front wheels 1 and the rear wheels 2 via the front wheel differential mechanism 73 and the rear wheel propeller shaft 59.

Next, a description will be given of a portion from the input shaft 21 to the first travel speed change device 50 inside the transmission case 10 with respect to the transmission system of the front wheels 1 and the rear wheels 2.

As shown in fig. 3, 4, 5, and 7, at a portion on the left side (one side) in the longitudinal direction of the input shaft 21, a first shift gear 51 is externally fitted to the input shaft 21 in a manner of turning integrally and operating slidably by a spline structure. The first shift gear 51 has a low-speed gear 51a and a high-speed gear 51 b.

As shown in fig. 3, 4, 7, and 9, the first travel transmission shaft 49 is supported on the lower side of the input shaft 21, slightly rearward in the left-right direction, so as to be parallel to the input shaft 21 when viewed from the side.

A middle-speed travel gear 54 (corresponding to a travel gear) is coupled to the left end (one side) of the first travel transmission shaft 49 in the longitudinal direction, a low-speed travel gear 53 (corresponding to a travel gear) is provided at the right end (the other side) of the first travel transmission shaft 49 in the longitudinal direction, and a high-speed travel gear 55 (corresponding to a travel gear) is coupled to the center portion of the first travel transmission shaft 49 in the longitudinal direction.

In the state shown in fig. 3 and 7, the first shift gear 51 is slid to the right (the other side) so that the high-speed gear 51b of the first shift gear 51 meshes with the high-speed travel gear 55 (the high-speed position of the first travel speed change device 50). When the first shift gear 51 in the state shown in fig. 3 and 7 is slidingly operated to the left (one side), the low speed gear 51a of the first shift gear 51 meshes with the middle speed running gear 54 (the low speed position of the first running speed change device 50).

As described above, as shown in fig. 4 and 7, the first travel speed change device 50 that freely performs 2-stage speed change is configured by the first shift gear 51, the middle speed travel gear 54, and the high speed travel gear 55 between the portion on the left side (one side) in the longitudinal direction of the input shaft 21 and the portion on the left side (one side) in the longitudinal direction of the first travel transmission shaft 49.

According to the above configuration, the power of the input shaft 21 is transmitted to the first travel transmission 50 (the first shift gear 51, the middle-speed travel gear 54, and the high-speed travel gear 55), 2-stage speed change is performed, and further, the power is transmitted to the first travel propeller shaft 49.

(8)

Next, a description will be given of a portion from the first running gear 50 to the second running gear 57 inside the transmission case 10 with respect to the transmission system of the front wheels 1 and the rear wheels 2.

As shown in fig. 3, 4, and 9, the second travel transmission shaft 56 is supported in the right-left direction at a position slightly rearward of the lower side of the first travel transmission shaft 49 in parallel with the input shaft 21 and the first travel transmission shaft 49 when viewed from the side.

As shown in fig. 3 and 4, at a portion on the right side (the other side) in the longitudinal direction of the second travel transmission shaft 56, the second shift gear 52 is externally fitted to the second travel transmission shaft 56 by a spline structure in a manner of turning integrally and operating freely slidably. The second shift gear 52 has a low-speed gear 52a and a high-speed gear 52 b.

In the state shown in fig. 3, the second shift gear 52 is slid to the left (one side) so that the high-speed gear 52b of the second shift gear 52 meshes with the high-speed travel gear 55 (high-speed position of the second travel speed change device 57). When the second shift gear 52 in the state shown in fig. 3 is slidingly operated to the right (the other side), the low-speed gear 52a of the second shift gear 52 meshes with the low-speed running gear 53 (the low-speed position of the second running speed change device 57).

As described above, as shown in fig. 3 and 4, the second travel speed change device 57 that freely performs 2-stage speed change is configured by the second shift gear 52, the low-speed travel gear 53, and the high-speed travel gear 55 between the portion on the right side (the other side) in the longitudinal direction of the first travel transmission shaft 49 and the portion on the right side (the other side) in the longitudinal direction of the second travel transmission shaft 56.

According to the above configuration, the power of the first travel transmission shaft 49 is transmitted to the second travel transmission device 57 (the second shift gear 52, the low-speed travel gear 53, and the high-speed travel gear 55), 2-step speed change is performed, and further, the power is transmitted to the second travel transmission shaft 56.

As shown in fig. 3 and 4, the high-speed running gear 55 is a running gear corresponding to the high-speed position (highest-speed position) of the first running speed change device 50 and also a running gear corresponding to the high-speed position (highest-speed position) of the second running speed change device 57, and is a common component of the first running speed change device 50 and the second running speed change device 57.

Since the high-speed running gear 55 is located at a portion on the center side in the longitudinal direction of the first running transmission shaft 49, the high-speed gear 51b of the first shift gear 51 is meshed with the high-speed running gear 55, and the high-speed gear 52b of the second shift gear 52 is meshed with the high-speed running gear 55, whereby the highest speeds of the first running speed change device 50 and the second running speed change device 57 can be obtained. The highest speeds of the first and second traveling transmission devices 50 and 57 are generally used in the case of traveling on a road.

At this time, as shown in fig. 3 and 4, the first shift gear 51 (high-speed gear 51b), the high-speed travel gear 55, and the second shift gear 52 (high-speed gear 52b) are aligned in a line at a central portion in the longitudinal direction of the first travel transmission shaft 49.

The small-diameter gear 114, the reverse operation clutch 27 (large-diameter gear 24), and the first traveling transmission 32 are disposed on the left side (one side) and the second traveling transmission 37 is disposed on the right side (the other side) with the high-speed traveling gear 55 as a boundary when viewed from above.

(9)

Next, a description will be given of a portion from the second travel transmission 57 to the rear wheel propeller shaft 59 inside the transmission case 10 with respect to the transmission system of the front wheels 1 and the rear wheels 2.

As shown in fig. 3 and 8, a bevel gear 58 (corresponding to a first bevel gear) is connected to the left (one) end of the second travel transmission shaft 56 in the longitudinal direction, and the bevel gear 58 (tooth portion) faces the second displacement member 52.

As a result, as shown in fig. 3 and 8, the bevel gear 58 is coupled to the second travel transmission shaft 56 such that the bevel gear 58 is positioned outward (leftward) of the intermediate travel gear 54 positioned at the left end (one side) in the longitudinal direction of the first travel transmission shaft 49, out of the low-speed travel gear 53, the intermediate travel gear 54, and the high-speed travel gear 55, and the bevel gear 58 (tooth portion) faces the second displacement member 52.

As shown in fig. 3, 8 and 9, the rear wheel propeller shaft 59 is supported at a lower portion of the rear portion of the transmission case 10 in the front-rear direction, and the rear wheel propeller shaft 59 is disposed below the insertion propeller shaft 38 and at the same height as the second travel propeller shaft 56 when viewed from the side. The rear wheel propeller shaft 59 is disposed at the center CL in the left-right direction of the machine body and is perpendicular to the second travel propeller shaft 56 when viewed from above.

As shown in fig. 3, 8 and 9, a bevel gear 60 (corresponding to a second bevel gear) is coupled to the rear wheel drive shaft 59 by a spline structure, and a bevel gear 58 meshes with the bevel gear 60. A transmission shaft (not shown) coupled to the rear portion of the rear wheel transmission shaft 59 extends rearward and is coupled to an input shaft (not shown) of the rear axle box 12.

According to the above configuration, as shown in fig. 3 and 8, the power of the second travel transmission shaft 56 is transmitted to the rear axle box 12 via the bevel gear 58, the bevel gear 60, and the rear wheel transmission shaft 59, and is transmitted to the rear wheels 2 on both left and right sides via the transmission shaft (not shown) and the transmission gear (not shown) inside the rear axle box 12.

As shown in fig. 8, the end portion of the second travel transmission shaft 56 on the left side (one side) in the longitudinal direction (bevel gear 58 side) is supported by 2 bearings 62. An end portion of the second travel transmission shaft 56 on the right side (the other side) in the longitudinal direction (the second shift gear 52 side) is supported by 1 bearing 63.

At this time, as shown in fig. 3, the bevel gear 60 is located between the bevel gear 58 and the second shift gear 52 as viewed from the rear, and the medium speed running gear 54 is disposed on the left side (one side) and the high speed running gear 55 is disposed on the right side (the other side) with respect to the bevel gear 60.

(10)

Next, the rear wheel propeller shaft 59 will be explained.

As shown in fig. 8 and 9, the sleeve portion 60a of the bevel gear 60 is elongated, the sleeve portion 60a of the bevel gear 60 is supported by a bearing 64, and the ring portion 60b having a larger diameter than the sleeve portion 60a of the bevel gear 60 is in contact with the bearing 64. The middle portion of the rear wheel drive shaft 59 is supported by a bearing 65.

As shown in fig. 8 and 9, the brake plate 66 is externally fitted to the sleeve portion 60a of the bevel gear 60 by a spline structure so as to rotate integrally with the sleeve portion 60a of the bevel gear 60 and freely slide. An annular receiving member 67 is provided between the bearing 64 and the brake disc 66. The annular pressing member 68 is fitted around the rear wheel transmission shaft 59 so as to be slidable and relatively rotatable. As described above, the brake pad 66 and the pressing member 68 constitute the brake portion 69.

As shown in fig. 8 and 9, the brake operating shaft 70 is rotatably supported by the transmission case 10, and the operating portion 70a of the brake operating shaft 70 having a circular cross section of 3/4 abuts against the lower side of the pressing member 68.

As shown in fig. 10 and 11, the brake pedal shaft 71 to which the brake pedal 61 is coupled is disposed between the insertion transmission shaft 38 and the rear wheel transmission shaft 59 in a side view, and is disposed in the left-right direction (the insertion transmission shaft 38 is disposed above the brake pedal shaft 71 in a side view). A connecting rod 72 is connected to an arm 70b of the brake operating shaft 70 and an arm 71a of the brake pedal shaft 71.

According to the above configuration, when the brake pedal 61 is depressed, the brake pedal shaft 71 is rotated by a small angle, the brake operating shaft 70 is also rotated by a small angle through the connecting rod 72, and the pressing member 68 is pressed against the brake pad 66 through the operating portion 70a of the brake operating shaft 70, thereby operating the brake portion 69 to the braking state.

At this time, since the transmission systems of the left and right front wheels 1 are configured as described in (11) below, the braking portion 69 not only applies a braking action to the left and right rear wheels 2 but also applies a braking action to the left and right front wheels 1.

As shown in fig. 8, in a state where the bevel gear 60 is coupled to the rear wheel drive shaft 59 by a spline structure, the fitting of the spline portion between the bevel gear 60 and the rear wheel drive shaft 59 is set to a tight state (a state of fitting a large diameter), and the bevel gear 60 and the rear wheel drive shaft 59 are coupled together tightly.

Thus, when the rear wheel transmission shaft 59 is pulled out rearward in a state where the bearing 65 and the brake operating shaft 70 shown in fig. 8 are pulled out, the bevel gear 60 is pulled out together with the rear wheel transmission shaft 59, and the bearing 64 and the brake portion 69 (the brake plate 66 and the pressing member 68) are pulled out together with the bevel gear 60.

(11)

Next, a portion from the second travel transmission 57 to the front wheel differential mechanism 73 inside the transmission case 10 and a steering mechanism of the front wheels 1 will be described with respect to the transmission system of the front wheels 1 and the rear wheels 2.

As shown in fig. 4 and 9, the steering shaft 74 is supported in the transmission case 10 so as to be vertically rotatable along the front wall portion 10d of the transmission case 10, and a planetary gear 74a is provided below the steering shaft 74.

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

As shown in fig. 9, the operating shaft 76 is supported at the rear side of the planetary gear 74a of the steering shaft 74 so as to be rotatable in the vertical direction at the bottom 10f of the transmission case 10, and the operating gear 76a at the upper portion of the operating shaft 76 meshes with the planetary gear 74a of the steering shaft 74. A steering member 91 is connected to a lower portion of the operating shaft 76, and the steering member 91 is connected to a support box (not shown) of the front wheels 1 on both left and right sides by a connecting rod 92.

Thus, when the steering handle 75 is operated, the steering shaft 74 is turned, the operating shaft 76 is turned, and the front wheels 1 are steered.

As shown in fig. 4 and 9, the steering mechanism of the front wheels 1, i.e., the steering shaft 74, the planetary gear 74a of the steering shaft 74, the operation shaft 76, and the operation gear 76a of the operation shaft 76 are disposed along the front wall portion 10d of the transmission case 10 and the bottom portion 10f of the transmission case 10.

As shown in fig. 9, the bottom portion 10f of the transmission case 10 is shaped to descend at the rear end (the rear portion of the bottom portion 10f of the transmission case 10 is lower than the front portion of the bottom portion 10f of the transmission case 10). Similarly, the operating gear 76a of the operating shaft 76 is also lowered along the bottom 10f of the transmission case 10 (the rear portion of the operating gear 76a of the operating shaft 76 is located lower than the front portion of the operating gear 76a of the operating shaft 76).

As shown in fig. 4 and 9, in a state where a virtual line K1 extending upward from the axial center of the operation shaft 76 is set, the front wheel differential mechanism 73 is disposed on the rear side of the virtual line K1 and on the upper side of the operation gear 76a of the operation shaft 76 when viewed from the side. The front wheel differential mechanism 73 is disposed so as to overlap a rear portion of the operating gear 76a of the operating shaft 76 and be positioned at a center CL in the left-right direction of the machine body when viewed from above. The second travel transmission shaft 56 is disposed above and behind the front wheel differential mechanism 73 when viewed from the side.

As shown in fig. 3, 4, and 9, a transmission gear 77 is connected to the right (other) end portion in the longitudinal direction of the second travel transmission shaft 56, a transmission gear 78 is connected to the right (other) end portion in the longitudinal direction of the housing 73a of the front wheel differential mechanism 73, and the transmission gear 77 is meshed with the transmission gear 78.

As shown in fig. 3, 4, and 9, a right (left) front wheel propeller shaft 79 extends rightward (left) from the front wheel differential mechanism 73, and the right (left) front wheel propeller shaft 79 is connected to the right (left) front wheel 1. The front wheel differential mechanism 73 is disposed at the center CL in the left-right direction of the machine body when viewed from above, and therefore the front wheel propeller shafts 79 on the left and right sides are equal in length.

Thus, as shown in fig. 3 and 4, the power of the second travel transmission shaft 56 is transmitted to the front wheel differential mechanism 73 (the housing 73a) via the transmission gears 77, 78, and is transmitted from the front wheel differential mechanism 73 to the right (left) front wheel 1 via the right (left) front wheel transmission shaft 79.

(12)

Next, the positional relationship of the input shaft 21, the first working propeller shaft 23, the second working propeller shaft 33, the first travel propeller shaft 49, the second travel propeller shaft 56, the plug propeller shaft 38, the rear wheel propeller shaft 59, and the front wheel differential mechanism 73 (front wheel propeller shaft 79) inside the transmission case 10 will be explained (first part).

As shown in fig. 9, the input shaft 21 is supported in the left-right direction in the vicinity of the center in the front-rear direction directly below the upper portion 10c of the transmission case 10 when viewed from the side (see (2) above). The first work transmission shaft 23 is supported at a position slightly below the front side of the input shaft 21 in the left-right direction when viewed from the side (see (2) above).

The second work transmission shaft 33 is supported directly below the upper portion 10c of the transmission case 10 and on the rear side of the input shaft 21 in the left-right direction when viewed from the side (see (4) above).

As shown in fig. 9, the first travel transmission shaft 49 is supported at a position slightly behind the lower side of the input shaft 21 (behind the first working transmission shaft 23) in the left-right direction when viewed from the side (see (7) above).

The second travel transmission shaft 56 is supported at a position slightly rearward of the lower side of the first travel transmission shaft 49 in the left-right direction when viewed from the side (see (8) above).

As shown in fig. 9, the front wheel differential mechanism 73 is disposed on the rear side of a virtual line K1 (a line extending upward from the axial center of the operating shaft 76 (see (11)) and on the upper side of the operating gear 76a of the operating shaft 76) when viewed from the side. The front wheel differential mechanism 73 is disposed so as to overlap with a rear portion of the operating gear 76a of the operating shaft 76 and be positioned at the center CL in the left-right direction of the machine body when viewed from above (see (11) above).

The second travel transmission shaft 56 is disposed above and behind the front wheel differential mechanism 73 when viewed from the side (see (11) above).

As shown in fig. 9, the input shaft 21, the first work propeller shaft 23, the second work propeller shaft 33, the first travel propeller shaft 49, the second travel propeller shaft 56, and the front wheel differential mechanism 73 (front wheel propeller shaft 79) are arranged in the left-right direction so as to be parallel to each other.

As shown in fig. 9, the implanting transmission shaft 38 is supported at the upper portion of the rear portion of the transmission case 10 in the front-rear direction, and the implanting transmission shaft 38 is disposed at the same height as the second working transmission shaft 33 and at the rear side of the second working transmission shaft 33 when viewed from the side.

The insertion transmission shaft 38 is disposed at the center CL in the left-right direction of the machine body and perpendicular to the second working transmission shaft 33 when viewed from above (see (5) above).

As shown in fig. 9, the rear wheel propeller shaft 59 is supported at the lower portion of the rear portion of the transmission case 10 in the front-rear direction, and the rear wheel propeller shaft 59 is disposed below the insertion propeller shaft 38 and at the same height as the second travel propeller shaft 56 when viewed from the side.

The rear wheel propeller shaft 59 is disposed at the center CL in the left-right direction of the machine body and perpendicular to the second travel propeller shaft 56 when viewed from above (see (9) above).

As shown in fig. 9, the plug-in drive shaft 38 and the rear wheel drive shaft 59 are arranged in the front-rear direction and parallel to each other, and the plug-in drive shaft 38 and the rear wheel drive shaft 59 are arranged perpendicular to the first working drive shaft 23, the second working drive shaft 33, the first travel drive shaft 49, the second travel drive shaft 56, and the front wheel differential mechanism 73 (front wheel drive shaft 79) as viewed from above.

(13)

Next, the positional relationship of the input shaft 21, the first working transmission shaft 23, the second working transmission shaft 33, the first traveling transmission shaft 49, the second traveling transmission shaft 56, the plug-in transmission shaft 38, the rear wheel transmission shaft 59, the front wheel differential mechanism 73 (front wheel transmission shaft 79), the first working transmission device 32, and the first traveling transmission device 50 in the transmission case 10 will be explained (second part).

The structure described in (12) above is as follows.

As shown in fig. 9, the input shaft 21, the second working transmission shaft 33, and the implant transmission shaft 38 are arranged at substantially the same height position when viewed from the side. The first working propeller shaft 23 and the first travel propeller shaft 49 are disposed below the input shaft 21 and the second working propeller shaft 33 and at substantially the same height position when viewed from the side.

As shown in fig. 9, the second travel propeller shaft 56 is disposed above and behind the front wheel differential mechanism 73 (front wheel propeller shaft 79) when viewed from the side, and the rear wheel propeller shaft 59 is disposed behind the second travel propeller shaft 56 at the same height as the second travel propeller shaft 56. Thus, the front wheel differential mechanism 73 (front wheel propeller shaft 79) is disposed on the front side of the meshing portion between the bevel gear 58 of the second travel propeller shaft 56 and the bevel gear 60 of the rear wheel propeller shaft 59, as viewed from the side.

As shown in fig. 9, the input shaft 21, the first working transmission shaft 23, the reverse working clutch 27, the first travel transmission shaft 49, the front wheel differential mechanism 73 (front wheel transmission shaft 79), the first working transmission device 32, the second working transmission device 37, the first travel transmission device 50, and the second travel transmission device 57 are arranged between a virtual line K1 (a line extending upward from the axial center of the operating shaft 76 (see (11)) and the rear wall portion 10p of the transmission case 10) and above the rear portion of the operating gear 76a of the operating shaft 76, as viewed from the side.

As shown in fig. 9, the input shaft 21, the first working transmission shaft 23, the second working transmission shaft 33, the first traveling transmission shaft 49, the second traveling transmission shaft 56, the plug transmission shaft 38, the rear wheel transmission shaft 59, the front wheel differential mechanism 73 (front wheel transmission shaft 79), the first working transmission device 32, the second working transmission device 37, the first traveling transmission device 50, and the second traveling transmission device 57 are disposed on the rear side and slightly away from the steering shaft 74 when viewed from the side.

Thus, the steering shaft 74 is disposed in the vertical direction between the front wall portion 10d of the transmission case 10 and the input shaft 21, the first working transmission shaft 23, the second working transmission shaft 33, the first travel transmission shaft 49, the second travel transmission shaft 56, the plug transmission shaft 38, the rear wheel transmission shaft 59, the front wheel differential mechanism 73 (front wheel transmission shaft 79), the first working transmission device 32, the second working transmission device 37, the first travel transmission device 50, and the second travel transmission device 57, as viewed from the side.

As shown in fig. 4 and 9, the rear wheel propeller shaft 59 is disposed so that the outer peripheral portion of the bevel gear 60 of the rear wheel propeller shaft 59 overlaps the outer peripheral portion of the front wheel differential mechanism 73 (housing 73a) when viewed from the front.

(14)

The operation system of the reverse operation clutch 27 will be explained below.

As shown in fig. 3 and 9, in the transmission case 10, the input shaft 16a and the output shaft 16b of the hydrostatic continuously variable transmission 16 are arranged in the front-rear direction in a state of facing in the left-right direction when viewed from the side, and thus the transmission shaft 19 coupled to the input shaft 16a of the hydrostatic continuously variable transmission 16 and the input shaft 21 coupled to the output shaft 16b of the hydrostatic continuously variable transmission 16 are arranged in the front-rear direction in a state of facing in the left-right direction when viewed from the side.

As shown in fig. 9, the clutch shaft 80 is supported in the transmission case 10 so as to be rotatable about a vertical axis P1 on the sleeve portion 10g of the upper portion 10c of the transmission case 10 and on the support portion 10h of the inner surface of the left portion 10b of the transmission case 10. The upper portion of the clutch shaft 80 protrudes outward (upward) from the sleeve portion 10g of the transmission case 10. A bifurcated clutch fork 80a is coupled to a lower portion of the clutch shaft 80. The clutch fork 80a extends rearward toward the reverse operation clutch 27, and engages with the displacement member 25.

As shown in fig. 9, an arm 80b is coupled to an upper portion of the clutch shaft 80, and the arm 80b is coupled to a shift lever 81 (see fig. 1 and 2) of the hydrostatic continuously variable transmission 16 via a coupling link (not shown).

As described above, the clutch shaft 80 and the clutch fork 80a of the clutch shaft 80 constitute the clutch operating portion 82 of the reverse operation clutch 27.

The hydrostatic continuously variable transmission 16 is configured to be continuously variable between a forward range and a reverse range with a neutral range interposed therebetween. As shown in fig. 2, 5 and 9, when the shift lever 81 is operated to the forward region (forward direction) and the forward side portion of the neutral region, the shift member 25 engages with the large diameter gear 24, and the reverse operation clutch 27 is in a transmission state.

As shown in fig. 5 and 9, when the shift lever 81 is operated from the forward side portion to the reverse side portion in the neutral region as described above (2), the clutch shaft 80 is rotated by the shift lever 81, the shift member 25 is operated by the clutch fork 80a of the clutch shaft 80 so as to be away from the large diameter gear 24, and the reverse operation clutch 27 is in the disengaged state. Even if the shift lever 81 is operated from the reverse side portion of the neutral region to the reverse region (in reverse), the disengaged state of the reverse operation clutch 27 can be maintained (see (2) above).

As shown in fig. 5 and 9, the clutch operating portion 82 (clutch shaft 80) is disposed between the first work transmission device 32 (the input shaft 21, the cylindrical shaft 28, the first work transmission shaft 23) and the steering shaft 74 when viewed from the side.

The clutch shaft 80 is disposed between the input shaft 16a (the propeller shaft 19) and the output shaft 16b (the input shaft 21) of the hydrostatic continuously variable transmission 16, and projects upward from the sleeve portion 10g of the upper side portion 10c of the transmission case 10, as viewed from the side. The clutch shaft 80 is disposed between the propeller shaft 19 and the input shaft 21 when viewed from above.

As shown in fig. 9, 11, and 12, the arm 80b is coupled to the upper portion of the clutch shaft 80 by a nut 86, and the arm 80b can be removed from the clutch shaft 80 by removing the nut 86.

By removing the arm 80b from the clutch shaft 80 as described above, the seal member 87 of the sleeve portion 10g of the transmission case 10 can be pulled out from above along the clutch shaft 80, and the seal member 87 can be easily replaced.

(15)

The following is a description of an operating system of the first traveling transmission 50.

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

As shown in fig. 7 and 9, the operating shaft 84 is supported by the sleeve portion 10k of the upper portion 10c of the transmission case 10 so as to be rotatable about the vertical axis P2, and the upper portion of the operating shaft 84 protrudes outward (upward) from the sleeve portion 10k of the transmission case 10. In the transmission case 10, a bifurcated arm 84a is coupled to a lower portion of the operating shaft 84, and the arm 84a extends rearward toward the first travel shift shaft 83 and engages with a small diameter portion 83b of the first travel shift shaft 83.

As described above, the first travel operation unit 85 of the first travel speed change device 50 is configured by the first travel displacement shaft 83 (the first travel fork 83a) and the operation shaft 84 (the arm 84 a).

As shown in fig. 7, 7 and 9, when the first travel shift shaft 83 is slid to the left (one side) by the operation shaft 84, the first travel shift shaft 83 (the first travel fork 83a) slides the first shift gear 51 to the left (one side), and the low speed gear 51a of the first shift gear 51 meshes with the medium speed travel gear 54 (the low speed position of the first travel speed change device 50).

As shown in fig. 7, 7 and 9, when the first travel shift shaft 83 is slid to the right (the other side) by the operation shaft 84, the first travel shift shaft 83 (the first travel fork 83a) slides the first shift gear 51 to the right (the other side), and the high-speed gear 51b of the first shift gear 51 meshes with the high-speed travel gear 55 (the high-speed position of the first travel transmission 50).

The upper portion 10c of the transmission case 10 has a positioning ball spring mechanism 88, and the first travel shift shaft 83 is held at the low speed position, the high speed position, or a neutral position between the low speed and the high speed position of the first travel speed change device 50 by the positioning ball spring mechanism 88.

As shown in fig. 7 and 9, the first travel operation portion 85 (the first travel shift shaft 83 (the first travel fork 83a) and the operation shaft 84 (the arm 84a)) is disposed between the first travel transmission device 50 (the input shaft 21, the first travel transmission shaft 49, the first shift gear 51) and the steering shaft 74 when viewed from the side.

The operating shaft 84 is disposed on the front side of the input shaft 16a (the propeller shaft 19) of the hydrostatic continuously variable transmission 16, and the first travel shift shaft 83 (the first travel fork 83a) and the operating shaft 84 (the arm 84a) are disposed on the upper side of the input shaft 16a (the propeller shaft 19) of the hydrostatic continuously variable transmission 16, as viewed from the side.

(16)

Next, the shift lever 93 connected to the operating shaft 84 of the first traveling transmission 50 will be described.

As shown in fig. 10, 11, 12 and 13, the shift lever 93 is formed of a round bar member, a coupling member 93a having a recessed groove shape is coupled to a lower portion of the shift lever 93 by welding, and a coupling hole 93b opens in the coupling member 93 a. Similarly, the coupling hole 84b is also opened at the upper portion of the operation shaft 84.

According to the above configuration, as shown in fig. 10, 11, 12 and 13, the coupling member 93a of the shift lever 93 is attached to the upper portion of the operating shaft 84, and the shift lever 93 is coupled to the operating shaft 84 by coupling the bolt 94 between the coupling hole 93b of the coupling member 93a of the shift lever 93 and the coupling hole 84b of the operating shaft 84. The shift lever 93 (operation shaft 84) and the clutch shaft 80 are located in the vicinity of the power steering mechanism 89 and the handle shaft 90, and the shift lever 93 (operation shaft 84), the clutch shaft 80, and the handle shaft 90 are parallel to each other.

As shown in fig. 10, 11, 12, and 13, a plate-like support member 96 is coupled to an upper portion of the power steering mechanism 89, and a U-shaped cutout portion 96a is formed in a rear portion of the support member 96.

As shown in fig. 12 and 13, in a state where the upper portion of the shift lever 93 is inserted into the cutout portion 96a of the support member 96, as shown in fig. 14, the coupling member 93a of the shift lever 93 is opened to the left (to the left or to the right) with respect to the cutout portion 96a of the support member 96 opened to the rear (to the front or to the rear). According to the above configuration, the orientation of the notch portion 96a of the support member 96 and the orientation of the coupling member 93a of the shift lever 93 are perpendicular (an example of intersection) when viewed from above.

Thus, as shown in fig. 14, the inclination of the shift lever 93 in the left-right direction with respect to the operation shaft 84 is supported by the notch portion 96a of the support member 96. The tilt of the shift lever 93 in the front-rear direction with respect to the operating shaft 84 is supported by a coupling member 93a of the shift lever 93 and a bolt 94.

As described in (15) above, in the state where the first traveling transmission device 50 is operated to the neutral position, as shown in fig. 14, the direction of the notched portion 96a of the support member 96 is perpendicular to the direction of the coupling member 93a of the shift lever 93 when viewed from above. Thus, in a state where the first traveling transmission device 50 is operated to the neutral position, the state where the shift lever 93 is supported by the cutout portion 96a of the support member 96, the coupling member 93a of the shift lever 93, and the bolt 94 can be 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 to be inclined 45 ° from the neutral position (see fig. 14) to one side (the other side). Thus, even when the first traveling transmission device 50 is operated to the low speed position and the high speed position by the shift lever 93, the state in which the shift lever 93 is supported by the notch portion 96a of the support member 96, the coupling member 93a of the shift lever 93, and the bolt 94 can be obtained.

As shown in fig. 9 and 13, by removing the shift lever 93 (coupling member 93a) and the bolt 94 from the operating shaft 84, the seal member 95 of the sleeve portion 10k of the transmission case 10 can be pulled out from above along the operating shaft 84, and the seal member 95 can be easily replaced.

(17)

The following is a description of an operating system of the first work transmission 32.

As shown in fig. 5, the first work shift shaft 100 is supported in a front portion of the right side portion 10a of the transmission case 10 so as to be slidable in the left-right direction, and the right portion of the first work shift shaft 100 projects outward (rightward) from the right side portion 10a of the transmission case 10. 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 engages with a right portion of the cylindrical member 31.

As shown in fig. 5, 10, and 12, the right side portion 10a of the transmission case 10 has a support portion 10n on the outside. The support portion 10n has an operation lever 101 to which an arm 101a having a triangular shape when viewed from above is connected, the arm 101a of the operation lever 101 is supported by the support portion 10n so as to be swingable about an axial center P3 in the vertical direction, and the arm 101a of the operation lever 101 is connected to the right portion of the first work displacement 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 operating portion 102 of the first work transmission device 32.

As shown in fig. 3, 5, and 6, when the operating lever 101 is operated to the front side, the first working shift shaft 100 is slidingly operated to the right (other side), the cylinder member 31 is slidingly operated to the right (other side), and the second gear 31b of the cylinder member 31 meshes with the first working gear 30a located at the end portion on the left (one side) among the plurality of first working gears 30 (the high speed position H of the first working speed changing device 32).

As shown in fig. 3, 5, and 6, when the operating lever 101 is operated to the rear side, the first working shift shaft 100 is slidingly operated to the left (one side), the cylinder member 31 is slidingly operated to the left (one side), and the first gear 31a of the cylinder member 31 meshes with the first working gear 30b located at the end portion on the right (other side) among the plurality of first working gears 30 (the low speed position L of the first working speed changing device 32).

The right side portion 10a of the transmission case 10 is provided with a positioning ball spring mechanism 103, and the first work shift shaft 100 is held at the low speed position L, the high speed position H, or a neutral position between the low speed position L and the high speed position H of the first work transmission device 32 by the positioning ball spring mechanism 103.

As shown in fig. 5, 9, and 10, the first work operating portion 102 (the first work displacement shaft 100 (the first work fork 100a)) is disposed between the first work transmission device 32 (the input shaft 21, the cylindrical shaft 28, the first work transmission shaft 23) and the steering shaft 74 when viewed from the side.

The first work operating unit 102 (the first work shift shaft 100 (the first work fork 100a)) is disposed between the input shaft 16a (the propeller shaft 19) of the hydrostatic continuously variable transmission 16 and the operating gear 76a of the operating shaft 76 when viewed from the side.

The first travel operation portion 85 (the first travel shift shaft 83 (the first travel fork 83a) and the operation shaft 84 (the arm 84a)) is disposed above the first work operation portion 102 (the first work shift shaft 100 (the first work fork 100a)) when viewed from the side.

(18)

The following describes an operation system of the second running transmission 57.

As shown in fig. 8, the second travel shift shaft 104 is supported at the rear of the left side portion 10b of the transmission case 10 so as to be slidable in the left-right direction, and the left portion of the second travel shift shaft 104 projects outward (leftward) from the left side portion 10b of the transmission case 10. As shown in fig. 1 and 2, a shift lever 112 provided on the left lateral side of the driver seat 111 is connected to the left portion of the second travel displacement shaft 104 via an operation arm 97 and a coupling mechanism (not shown).

As shown in fig. 8, a second travel fork 104a is coupled to a right portion of the second travel shift shaft 104, and the second travel fork 104a extends downward toward the second work transmission device 57 and engages with the second shift gear 52.

As described above, the second travel operation unit 105 of the second travel transmission 57 is configured by the second travel shift shaft 104 and the second travel fork 104a of the second travel shift shaft 104.

As shown in fig. 8, 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) slides the second shift gear 52 to the left (one side), and the high-speed gear 52b of the second shift gear 52 meshes with the high-speed travel gear 55 (the high-speed position of the second travel speed change device 57).

As shown in fig. 8, 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) slides the second shift gear 52 to the right (the other side), and the low-speed gear 52a of the second shift gear 52 meshes with the low-speed travel gear 53 (the low-speed position of the second travel speed change device 57).

The transmission case 10 has a positioning ball spring mechanism 106 at the left side portion 10b thereof, and the second travel shift shaft 104 is held at a low speed position, a high speed position, or a neutral position between the low speed and high speed positions of the second travel speed change device 57 by the positioning ball spring mechanism 106.

As shown in fig. 8, 9 and 12, the second travel shift shaft 104 is disposed between the second working transmission shaft 33 and the planting transmission shaft 38 (bevel gear 40), and the second travel transmission shaft 56 and the rear wheel transmission shaft 59 (bevel gear 60), as viewed from the side and from the rear.

(19)

The following is a description of the operating system of the second work transmission 37.

As shown in (4) and fig. 5, the cylindrical portion 33a of the second work transmission shaft 33 and the right side portion 10a of the transmission case 10 are provided with the operation shaft 36 that is slidable, and the right portion of the operation shaft 36 protrudes outward (rightward) from the right side portion 10a of the transmission case 10.

As described above, the second work operation portion 107 of the second work transmission device 37 is constituted by the operation shaft 36.

As shown in fig. 5, 10, 11, and 12, a support member 108 bent in a U-shape when viewed from the front is coupled to the outside of the right side portion 10a of the transmission case 10. An operating lever 109 formed by bending a round bar is supported by the support member 108 so as to be swingable about a vertical axis P4, and a bifurcated arm 109a connected to the operating lever 109 is connected to the right portion of the operating shaft 36.

According to the above configuration, the operating shaft 36 can be slidably operated by operating the operating lever 109 about the axial center P4, and the second working transmission device 37 is operated to the 1 st position F1 to the 4 th position F4 by slidably operating the operating shaft 36 as shown in the above (4) and fig. 5 and 6.

The right side portion 10a of the transmission case 10 is provided with a positioning ball spring mechanism 110, and the operating shaft 36 is held at the 1 st position F1 to the 4 th position F4 of the second working transmission 37 by the positioning ball spring mechanism 110.

(first other embodiment of the invention)

In the above-described "embodiment," the structures of the hydrostatic continuously variable transmission 16 and the transmission 10 inside and outside may be arranged in left and right reverse directions (or may be arranged in left and right alternate directions).

When the above-described structure is employed, the right side is one side (the hydrostatic continuously variable transmission 16 side), and the left side is the other side (the side opposite to the hydrostatic continuously variable transmission 16).

(second other embodiment of the invention)

In the above-described "embodiment," the structures provided inside and outside the transmission 10 may be arranged in left and right reverse directions (may be arranged alternately in the left and right directions) in a state where the hydrostatic continuously variable transmission 16 is provided in the left side portion 10b of the transmission 10.

When the above-described structure is employed, 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 other embodiment of the invention)

The first work transmission 32 shown in fig. 3, 4, 5 and 6 may be designed to freely perform 3-stage or 4-stage shift in addition to 2-stage shift. The second work transmission 37 may be designed to freely perform 3-, 5-or 6-stage shift in addition to 4-stage shift.

(fourth other embodiment of the invention)

The first traveling transmission 50 shown in fig. 3, 4, 7, and 8 may be designed to freely perform 3-stage or 4-stage transmission in addition to 2-stage transmission. The second traveling transmission 57 can be designed to freely perform 3-stage or 4-stage shift in addition to 2-stage shift.

(fifth other embodiment of the invention)

The front wheel differential mechanism 73 shown in fig. 9 may be disposed directly above a virtual line K1 (a line extending upward from the axial center of the operation shaft 76 (see (11)) and positioned above the operation gear 76a of the operation shaft 76) or may be disposed forward of the virtual line K1 and positioned above the operation gear 76a of the operation shaft 76, as viewed from the side. The second travel propeller shaft 56 shown in fig. 9 may be disposed directly above the front wheel differential mechanism 73, or may be disposed above and in front of the front wheel differential mechanism 73, as viewed from the side.

(sixth other embodiment of the invention)

The operating gear 76a of the operating shaft 76 shown in fig. 9 may be formed as a sector gear (a semicircular shape without a rear portion).

When the above-described configuration is adopted, the front wheel differential mechanism 73 is disposed on the rear side of the virtual line K1 (the line extending upward from the axial center of the operation shaft 76 (see (11))) above) and on the upper side of the operation gear 76a of the operation shaft 76 when viewed from the side, and when the front wheels 1 are steered to the forward position in the above state, the operation gear 76a of the operation shaft 76 does not exist directly below the front wheel differential mechanism 73 (the front wheel differential mechanism 73 is located directly above the rear portion of the operation gear 76a of the operation shaft 76).

Then, when the operation gear 76a of the operation shaft 76 is rotated to steer the front wheel 1 to the right (left) side, the right portion (left portion) of the operation gear 76a of the operation shaft 76 is rotated to the rear side, and when viewed from the side, the right portion (left portion) of the operation gear 76a of the operation shaft 76 enters the lower side of the front wheel differential mechanism 73, and the front wheel differential mechanism 73 is disposed at a position above the operation gear 76a of the operation shaft 76.

The input shaft 21, the first working transmission shaft 23, the reverse working clutch 27, the first travel transmission shaft 49, the first working transmission 32, and the first travel transmission 50 shown in fig. 9 are in the same state as the front wheel differential mechanism 73.

In a state where the operating gear 76a of the operating shaft 76 and the operating gear 76a of the operating shaft 76 shown in fig. 9 are formed as sector gears, the operating gear 76a of the operating shaft 76 may be disposed in a horizontal state, in addition to a rear end-down state.

(seventh other embodiment of the invention)

As shown in fig. 16, the gear ratio at high speed position H and the gear ratio at low speed position L of first work transmission device 32, and the gear ratio at 1-speed position F1, the gear ratio at 2-speed position F2, the gear ratio at 3-speed position F3, and the gear ratio at 4-speed position F4 of second work transmission device 37 may be set so that the low speed portion of high speed side shift range R1 overlaps the high speed portion of low speed side shift range R2 of 2 shift ranges R1 and R2 in 2 shift ranges R1 and R2.

In the state shown in fig. 16, the 3-speed position FF3 of the first and second work speed change devices 32, 37 is located between the 5-speed positions FF5 and 6-speed position FF6 of the first and second work speed change devices 32, 37, and the 4-speed position FF4 of the first and second work speed change devices 32, 37 is located between the 6-speed positions FF6 and 7-speed position FF7 of the first and second work speed change devices 32, 37.

At this time, in a portion RR where the 2 shift ranges R1, R2 overlap, the speed ratio at the high speed position H and the speed ratio at the low speed position L of the first work transmission device 32 are set, and the speed ratio at the 1-speed position F1, the speed ratio at the 2-speed position F2, the speed ratio at the 3-speed position F3, and the speed ratio at the 4-speed position F4 of the second work transmission device 37 are set, so that the 3-speed position FF3 (speed ratio), the 4-speed position FF4 (speed ratio), the 5-speed position FF5 (speed ratio), and the 6-speed position FF6 (speed ratio) of the first work transmission device 32 and the second work transmission device 37 are different (do not overlap) with each other.

In fig. 16, the 4-speed position FF4 (gear ratio) of the first and second work transmissions 32, 37 may also be located between the 5-speed position FF5 (gear ratio) and the 6-speed position FF6 (gear ratio) of the first and second work transmissions 32, 37.

When the structure described above is adopted, the overlapping portion RR of the 2 shift ranges R1, R2 is smaller than the state shown in fig. 16.

(availability in industry)

The present invention can be applied not only to a riding type rice transplanter but also to a riding type direct seeder having a direct seeding device as an operation device.

Claims (8)

1. A paddy field working machine is characterized in that,

an input shaft, a working transmission shaft, a first running transmission shaft, a second running transmission shaft, and a front wheel transmission shaft are provided inside the transmission case, power is transmitted to the input shaft, the working transmission shaft, the first running transmission shaft, the second running transmission shaft, and the front wheel transmission shaft are parallel to each other in the left-right direction,

a first running speed change device that transmits power to front wheels and rear wheels is provided between a portion on one side in a longitudinal direction of the input shaft and a portion on one side in a longitudinal direction of the first running transmission shaft,

a work transmission device is provided between the other side portion in the longitudinal direction of the input shaft and the other side portion in the longitudinal direction of the work transmission shaft, and the power of the work transmission device is transmitted to a work device provided in the machine body,

a second running gear transmission device that transmits power of the first running gear transmission device to the rear wheel via the second running gear transmission device is provided between a portion on the other side in the longitudinal direction of the first running gear shaft and a portion on the other side in the longitudinal direction of the second running gear shaft,

a first transmission gear provided in a portion on the other side in the longitudinal direction of the second running transmission shaft and a second transmission gear provided in a portion on the other side in the longitudinal direction of a front wheel differential mechanism, the front wheel transmission shaft extending from the front wheel differential mechanism, power of the first running transmission being transmitted to the front wheel via the second running transmission and the front wheel differential mechanism,

a steering shaft of front wheels is disposed in the transmission case in a vertical direction between a front wall portion of the transmission case and the input shaft, the first travel speed changing device, and the work speed changing device, the steering shaft is operated by a steering handle, a planetary gear is provided at a lower portion of the steering shaft,

an operation shaft for steering the front wheels is disposed in the vertical direction at a portion of the bottom of the transmission case located on the rear side of the planetary gear, and an operation gear is provided on the upper portion of the operation shaft,

by engaging the planetary gear with the operating gear, the operation of the steering handle is transmitted to the front wheels via the steering shaft and the operating shaft, steering operation is performed on the front wheels,

an operation shaft for performing a running operation of the first running gear via an arm is linked to a running displacement shaft that is linked to the first running gear via a running fork,

a virtual line extending upward from the axis of the operating shaft is set,

the input shaft, the first travel transmission shaft, the working transmission shaft, the second travel transmission shaft, the front wheel transmission shaft, the first travel transmission device, and the working transmission device are arranged between the virtual line and a rear wall portion of the transmission case when viewed from the side,

the arm and the travel displacement shaft are disposed between the virtual line and a front wall portion of the transmission case when viewed from the side.

2. The paddy field working machine according to claim 1,

the power of the input shaft is transmitted to the first running transmission shaft via the first running transmission, the first running transmission shaft has a small-caliber gear, the working transmission shaft has a large-caliber gear, and by engaging the small-caliber gear with the large-caliber gear,

the power of the input shaft is transmitted to the first running transmission shaft, the small-caliber gear, the large-caliber gear and the working transmission shaft,

the plurality of working gears are externally fitted to the input shaft so as to be relatively rotatable, and the working transmission device is configured from the working drive shaft to the working gears.

3. The paddy field working machine according to claim 2,

and a reverse operation clutch is arranged between the large-caliber gear and the operation transmission shaft, and the reverse operation clutch is operated to a transmission state when the machine body moves forwards and is operated to a cutting state when the machine body moves backwards.

4. The paddy field working machine as claimed in claim 3,

the reverse operation clutch has a displacement member that rotates integrally with the operation transmission shaft and slides freely,

the shift member is slidably operated to engage the shift member with the large-diameter gear to form a transmission state, and the shift member is slidably operated to disengage the shift member from the large-diameter gear to form a cut-off state.

5. The paddy field working machine according to any one of claims 1 to 4,

the first travel speed change device has a first shift gear supported on the input shaft in an integrally revolving and freely sliding manner, and a plurality of travel gears fixed to the first travel transmission shaft such that the first shift gear meshes with one of the plurality of travel gears,

the second running transmission device has a second shift gear and a plurality of running gears, the second shift gear being supported on the second running transmission shaft in an integrally revolving and freely sliding manner so as to mesh with one of the plurality of running gears,

among the plurality of running gears, a running gear corresponding to the highest speed position of the first running transmission and the second running transmission is located at a portion on the center side in the longitudinal direction of the first running propeller shaft.

6. A paddy field working machine as claimed in claim 5,

a first bevel gear facing the second shift gear is provided on the second travel transmission shaft, the first bevel gear being located at a position that is further outward than the travel gear at one end in the longitudinal direction of the first travel transmission shaft,

a rear wheel transmission shaft for transmitting power to the rear wheel is disposed perpendicularly to the second travel transmission shaft such that a second bevel gear of the rear wheel transmission shaft is engaged with the first bevel gear.

7. The paddy field working machine as claimed in any one of claims 2 to 4,

the operation speed change device is provided with a first gear and a second gear which can rotate integrally on a cylindrical component, the cylindrical component is externally embedded on the operation transmission shaft in a mode of rotating integrally and sliding freely,

the work transmission device shifts gears by a manner in which

Sliding the cylindrical member to one side to cause the first gear to mesh with an end portion of the plurality of working gears located on the other side; and

sliding the cylindrical member toward the other side to cause the second gear to mesh with the working gear located at one end portion of the plurality of working gears,

the work gear located at one end of the plurality of work gears has the smallest diameter among the plurality of work gears, and the work gear located at the other end of the plurality of work gears has the largest diameter among the plurality of work gears.

8. The paddy field working machine as claimed in any one of claims 2 to 4,

a hydrostatic continuously variable transmission is provided on the right or left side of the transmission,

power of an engine is transmitted to the hydrostatic continuously variable transmission, 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 running transmission shaft, and one side in the longitudinal direction of the working transmission shaft are the hydrostatic continuously variable transmission side,

the other side in the long side direction of the input shaft, the other side in the long side direction of the first travel transmission shaft, and the other side in the long side direction of the working transmission shaft are the sides opposite to the hydrostatic continuously variable transmission.

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