JPH11127613A - Working vehicle for paddy field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working vehicle with side brakes capable of controlling each of light-and-left rear wheels independently, enabling an easy turning operation conducted by applying the side brake on the side of the center of turn. SOLUTION: This working vehicle is provided with an operating means capable of applying the side brake 45 on the center of turn when the front wheels 1 are turned from the forthright direction to the right of left direction and with a manual operating means 43 capable of manually controlling the operating means between activation and inactivation. Further, it employs a check means 68 designed to shift the manual operating means 43 to the stop position by being linked with a speed change gear when the speed change gear is shifted from the working position to the road running position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling system in a paddy field working vehicle such as a riding type rice transplanter or a riding type direct sowing machine.

[0002]

2. Description of the Related Art In a riding type rice transplanter, which is an example of a paddy field working vehicle, a side brake capable of braking a right rear wheel, a side brake pedal for operating the side brake to a braking side, and a left rear wheel capable of braking. And a side brake pedal for operating the side brake on the braking side. As a result, when one planting process is completed and the aircraft reaches the ridge, the driver lifts the seedling planting device, operates the steering wheel to steer the front wheel, and simultaneously rotates Depress the side brake pedal and make a small turn around the ridge to enter the next planting process.

[0003]

In a paddy field vehicle such as a riding type rice transplanter, when turning as described above, the driver lifts the working device, steers the front wheels using the steering wheel, and turns the center of the turning center. Since many operations need to be performed, such as depressing the side brake pedal, there is room for improvement in terms of operability during turning. SUMMARY OF THE INVENTION It is an object of the present invention to provide a paddy field working vehicle so that a turning operation can be easily performed.

[0004]

[Means for Solving the Problems]

[I] According to the feature of claim 1, if the driver has previously operated the operating means with an artificial operation tool, the front wheel is steered to the right or left from the straight traveling position during turning. Then, the side brake on the turning center side is automatically operated to the braking side by the operating means, and a small turn is performed.

[0005] In general, a transmission for traveling a paddy field work vehicle is provided with a road travel position and a work travel position. The road travel position is set at a relatively high speed, and the work travel position is set at a relatively low speed. I have. According to the features of claim 1,
When the speed change device for traveling is shifted from the work traveling position to the road traveling position, the artificial operation tool is automatically operated to the stop position in conjunction with the shift operation, and the operating means is changed from the operating state to the stopped state. Operated automatically. Therefore, in a state in which the transmission for traveling is traveling at a high speed in which the speed is shifted to the road traveling position, even if the front wheel is steered to the right or left from the straight traveling position to make a turn, the side brake on the turning center side is provided. Is not operated on the braking side. Thus, when the vehicle is turning at a high speed, the side brake on the turning center side is automatically operated to the braking side, thereby avoiding a state in which the vehicle is suddenly turned and the riding comfort is deteriorated.

In this case, when the transmission is shifted from the work traveling position to the road traveling position, the artificial operation tool is moved to the stop position in conjunction with the gear shifting operation. By moving the artificial operation tool to the stop position and visually observing the state where the artificial operation tool is being operated at the stop position, it is possible to recognize that the operating means has been automatically operated to the stop state. . Therefore, it is possible to avoid a situation in which the driver has a misunderstanding that the operating means is still operated in the operating state without the driver noticing that the operating means has been operated in the stop state.

[II] In addition to the side brake, the paddy field work vehicle is operable in a standard state in which the front wheels and the rear wheels are driven at substantially the same speed, and in a speed-up state in which the front wheels are driven at a higher speed than the rear wheels. It has been proposed to provide a front wheel transmission.
Thus, according to the second aspect of the present invention, if the driver operates the first and second operation means in advance by using the first and second artificial operation tools, the front wheel is shifted from the straight traveling position to the right during turning. Alternatively, when the steering operation is performed to the left, the side brake on the turning center side is automatically operated to the braking side by the first operation means, and the front wheel transmission is automatically changed from the standard state to the speed increasing state by the second operation means. When operated, a small turning is performed by the braking action on the rear wheel on the turning center side and the pulling action in the turning direction by the front wheel.

In general, a transmission for traveling a paddy field work vehicle is provided with a road traveling position and a work traveling position. The road traveling position is set at a relatively high speed, and the work traveling position is set at a relatively low speed. I have. According to the features of claim 2,
When the traveling transmission is shifted from the work traveling position to the road traveling position, the first and second gears are interlocked with this shifting operation.
The artificial operation tool is automatically operated to the stop position, and the first and second operation means are automatically operated from the operating state to the stopped state. Therefore, in a state in which the transmission for traveling is traveling at a high speed in which the speed is shifted to the road traveling position, even if the front wheel is steered to the right or left from the straight traveling position to make a turn, the side brake on the turning center side is provided. Is not operated on the braking side, and the front wheel transmission is not operated in the speed increasing state and remains in the standard state. As a result, when turning while driving at high speed, the side brake on the turning center side is automatically operated to the braking side,
The state in which the front wheel transmission is operated from the standard state to the speed increasing state to avoid a sudden turning state and a poor ride quality is avoided.

In this case, when the traveling transmission is shifted from the work traveling position to the road traveling position, the first and second artificial operating tools move to the stop position in conjunction with the shifting operation. The first and second movements of the first and second artificial operating tools to the stop position and the state in which the driver is operating the first and second artificial operating tools at the stop positions are visually recognized by the driver. It is possible to recognize that the two operation means have been automatically operated to the stop state. Therefore, the driver does not realize that the first and second operating means are operated in the stop state, and the driver misunderstands that the first and second operating means are still operated in the operating state. Can be avoided.

[III] According to the feature of claim 3, similar to the case of claim 1 or 2, the "action" described in the above [I] or [II] is provided. Has "action". When turning with the side brake on the turning center side braking to the rear wheel on the turning center side, if the braking force of the side brake on the turning center side is strong, a sufficient small turning can be performed, while the turning center The rear wheels on the side tend to roughen the rice field. Conversely, if the braking force of the side brake on the turning center side is weak, it is difficult to perform a sufficiently small turn, but the rear surface of the turning center side rarely roughens the rice field.

According to the third aspect of the present invention, when it is desired to make a small turning turn as small as possible, for example, when the steering angle of the front wheel from the straight traveling position is large, the braking force of the side brake on the turning center side is increased. . Conversely, when it is not necessary to make a very small small turn such as when the steering angle of the front wheel from the straight traveling position is small, the braking force of the side brake on the turning center side becomes weak. As described above, when it is not necessary to make a very small small turn, by weakening the braking force of the side brake on the turning center side so as not to unnecessarily apply braking to the rear wheel on the turning center side, The state where the rice field is roughened by the rear wheel on the turning center side can be reduced.

[IV] According to the feature of claim 4, similar to the case of claim 2 or 3, the "action" described in the above [II] [III] is provided, and in addition to this, the following Has "action". An operation member for operating the front wheel transmission from the standard state to the speed increasing state by engaging the second operation means of the front wheel transmission with the operated part and moving the operated part, and mechanically operating the front wheel and the operation member. If the front wheel is steered right or left from the straight traveling position, the operation of the front wheel is transmitted to the operating member via the linking mechanism, and the operated member is operated by the operating member. Is operated,
The front wheel transmission is operated from the standard state to the speed increasing state.

According to a fourth aspect of the present invention, when the second artificial operation tool is operated to the stop position, the operation member is separated from the operated portion. Thus, even if the front wheel is steered to the right or left from the straight traveling position, the operated portion is not operated by the operation of the front wheel, and the second operating means is in a stopped state. In this case, while the linking mechanism that mechanically links the front wheel and the operating member is linked, the operating member located at the end of the linking mechanism is separated from the operated portion by operating the second operating means. Can be operated in a stopped state, so that it is not necessary to adopt a complicated structure in which a part in the middle of the linking mechanism is separated to obtain a stopped state of the second operating means.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) As shown in FIG. 1, the airframe is supported by a pair of left and right front wheels 1 having no lugs and a pair of right and left rear wheels 2 having a wide lug 2A, and seedlings are planted at the rear of the airframe. The attachment device 3 is connected by a link mechanism 7 so as to be able to move up and down freely,
A riding type rice transplanter, which is an example of a four-wheel drive type paddy field working vehicle, is configured.

Next, the traveling transmission system of the riding type rice transplanter will be described. As shown in FIG. 2 and FIG. 1, the power of the engine 4 arranged at the front part of the fuselage
Via a main clutch 12 and a transmission shaft 16 supported by a bearing 14, a hydrostatic continuously variable transmission 5 that can be steplessly operated to move forward and backward, and can be freely shifted to a high-speed position H and a low-speed position L. The transmission is transmitted to the auxiliary transmission 17 installed in the transmission case 6 by the rear wheel differential device (not shown).
And is transmitted to the left and right rear wheels 2 via the. The power branched immediately before the rear wheel differential device is transmitted to the left and right front wheels 1 via the transmission shaft 18, the front wheel transmission 9, and the front wheel differential device 10 (see FIG. 4).

The rear axle case 8 is filled with lubricating oil to form an oil bath. As shown in FIGS. 11 and 12, the rear axle case 8 has a support case 8 for supporting the rear wheel 2.
A is connected to the pipe frame 69, and the pipe frame 69 and the center of the rear axle case 8 are brackets 69A.
Are connected via An O-ring 70 is attached between the support case 8A and the pipe frame 69, and a connecting portion between the support case 8A and the pipe frame 69 on one side includes:
A shim plate 71 for adjusting the interval is inserted.

As a result, the entire rear axle case 8 is reinforced by the pipe frame 69, and the lubricating oil of the rear axle case 8 (support case 8A) is
9 and back and forth. When hydraulic oil for a power steering mechanism (not shown) described later is sucked from the lateral side of the transmission case 6, the lubricating oil for the rear axle case 8 (support case 8A) is
By moving back and forth through 9, the unpleasant sound at the time of suction and the rise in the temperature of the lubricating oil can be suppressed.

(2) Next, the configuration near the front wheel transmission 9 will be described. As shown in FIGS. 2 and 4, the front wheel transmission 9 is fixed to the front of the body, and a boss 9 </ b> A at the front end of the front wheel transmission 9 and the support member 15 fixed to the front of the body include: A front axle case 11 is supported so as to freely roll around a front-rear axis X, and front wheels 1 are supported at both ends of the front axle case 11 so as to be steerable left and right. FIG.
As shown in FIG. 2, in the front wheel transmission 9, a first standard gear 21 and a first speed increasing gear 22 are fixed to an input shaft 19 connected to a transmission shaft 18, and are relatively rotatably supported by an output shaft 20. Second standard gear 23 and second speed increasing gear 24
Are engaged with the first standard gear 21 and the first speed increasing gear 22.

The shift member 25 has a spline structure,
A friction multi-plate type speed increasing clutch 27 is provided between the second speed increasing gear 24 and the output shaft 20 so as to be slidable and integrally rotatable around the output shaft 20. The front wheel differential device 10 is mounted on the front axle case 11 via a bearing 47.
Are supported, and the gear 20A of the output shaft 20 of the front wheel transmission 9 is engaged with the input gear 50 of the front wheel differential device 10. Transmission shaft 5 from front wheel differential device 10 to one front wheel 1
2, a differential lock member 51 is slidably fitted outside in a spline structure, and the differential lock member 51 is slid by an operating member 55 so as to be structured in the case 46 of the front wheel differential device 10. Lock operation.

As a result, when the shift member 25 is slid to the right on the paper as shown in FIG. 4 to engage with the second standard gear 23, the power from the transmission shaft 18 causes the power from the first and second standard gears 21, Through the output shaft 23, the output shaft 20, the front wheel differential device 10, and the transmission shaft 52, the power is transmitted to the left and right front wheels 1 in a standard state in which the front wheel 1 and the rear wheel 2 are driven at substantially the same speed. When the shift member 25 is slid leftward on the paper from the state shown in FIG. 4 and the speed-increasing clutch 27 is pressed to operate the speed-increasing clutch 27 on the transmission side, the power from the transmission shaft 18 increases in the first and second directions. Speed gears 22, 24, output shaft 20, front wheel differential device 1
0 and the transmission shaft 52 are transmitted to the left and right front wheels 1 in a speed-up state in which the front wheels 1 are driven at a higher speed than the rear wheels 2.

(3) Next, the operation structure of the front wheel transmission 9 will be described. As shown in FIGS. 4 and 7, a shift fork 34 that slides the shift member 25 of the front wheel transmission 9 is supported by an operation shaft 26 that is slidable in the axial direction. 23 side (standard state side)
Has been energized. As shown in FIGS. 2, 3, and 7, the operation shaft 35 is rotatably supported by the front wheel transmission 9, and the operation pin 35A deviated from the rotation center of the operation shaft 35 is engaged with the shift fork 34. By rotating the operation shaft 35, the shift fork 34 and the shift member 25
Can be slid.

As shown in FIGS. 2 and 3, a pitman arm 29 is provided which is linked to a steering handle 28 (see FIG. 1) and is operated to swing left and right by a power steering mechanism (not shown). The knuckle arm 30 and the pitman arm 29 are connected by a tie rod 31. As shown in FIGS. 2, 3, and 6, a cam plate 32 is fixed to the pitman arm 29, and a pin 33A of a cam arm 33 that is swingably supported around a longitudinal axis P1 of the fuselage fixing portion is connected to the cam plate 32. Of the cam hole 32A. An operation arm 36 is fixed to an operation shaft 35 of the front wheel transmission 9, and a link rod 37 is connected between the operation arm 36 and the cam arm 33.

With the above structure, the front wheel 1 is controlled by the steering wheel 28 and the power steering mechanism shown in FIG.
When the (pitman arm 29) is steered from the straight traveling position by more than the right or left set angle, the cam hole 32A and the pin 3
3A, the cam arm 33 is pivoted to the left in FIG. 3 to move the link rod 37 to the cam arm 3.
The pull operation is performed to the third side. Thereby, the operation shaft 35 shown in FIGS. 3 and 7 is rotated, and the operation pin 3 of the operation shaft 35 is rotated.
4A, the shift fork 34 is slid to the left in FIG. 4, the shift member 25 presses the speed-increasing clutch 27 and operates on the transmission side, and the front wheel 1 is driven at a higher speed than the rear wheel 2. It becomes a speed state.

In the above state, when the front wheel 1 (pitman arm 29) is steered from the straight traveling position by more than the right or left set angle, the front wheel transmission 9 is operated from the standard state to the speed increasing state. State. On the other hand, even if the front wheel 1 (pitman arm 29) is steered from the straight traveling position by more than the right or left set angle, the front wheel transmission 9 is not operated in the speed increasing state and remains in the standard state. The operation structure for the stop state will be described next.

As shown in FIGS. 5 and 7, the boss member 38 is supported by the bracket 40A of the right body frame 40 so as to be rotatable around the horizontal axis P2, and a pair of first boss members 38 are fixed to the boss member 38. The first arm 38A is engaged with the operation shaft 35, and the shift fork 34 and the shift
A spring 39 biasing the standard gear 23 side (standard state side) is connected to the operation shaft 35. A balance arm 41 is swingably supported around a horizontal axis P3 of the right body frame 40, and a second arm 38B fixed to the boss member 38 and one end of the balance arm 41 are connected by a link rod 42. Have been. As shown in FIG. 5 and FIG.
A second operation lever 44 is fixed to the other end of the first unit, and the second operation lever 44 is disposed so as to protrude to the front right side of the body.

The state shown in FIGS. 1 and 5 is a state in which the second operation lever 44 is pulled up and operated to the operating position. As shown in FIG. 7, the operation pin 35A of the operation shaft 35 is connected to the shift fork 34. Is engaged. Thereby, the front wheel 1
When the (pitman arm 29) is steered from the straight traveling position by more than the right or left set angle, the front wheel transmission 9 is operated from the standard state to the speed increasing state.

Conversely, when the second operation lever 44 is pushed down to the stop position from the state shown in FIGS. 1 and 5, the balance arm 41 and the first arm 38A of the boss member 38 cause
The operation shaft 35 is slid to the right in FIG. 7, and the operation pin 35 </ b> A of the operation shaft 35 is separated from the shift fork 34. Thus, even if the front wheel 1 (pitman arm 29) is steered from the straight traveling position by more than the right or left set angle, the shift fork 34 is not slid but the operation shaft 35 is only idled, and the front wheel transmission 9 Will be in a stopped state where it will remain in the standard state.

(4) As shown in FIG.
Pair of left and right side brakes 45 that can independently brake
Are provided in the rear axle case 8. Next, the operation structure of the side brake 45 will be described. As shown in FIG. 11, for each of the right and left side brakes 45,
The right and left brake operation mechanisms 48 are provided, and the right and left brake operation mechanisms 48 are configured as follows. As shown in FIGS. 8 and 9, the right and left brake operation mechanisms 48 are rotatable around the horizontal axis P4. The side brake pedal 53 is fixed to a boss member 49 supported by the boss member 49, and the first arm 49 </ b> A fixed to the boss member 49 and the side brake 45 are connected by a link rod 54. As shown in FIG. 1 and FIG. 11, the side brake pedal 53 is
The side brake 45 is arranged side by side with the operation lever 44, and the side brake 45 can be operated to the braking side by depressing the side brake pedal 53.

As shown in FIG. 8 and FIG.
An elongated hole 49C is formed in the first arm 49A, and a pin 56A of a separately provided link arm 56 is inserted into the elongated hole 49C of the first arm 49A. Linking arm 5
6, a vertically elongated recess 56B is formed, and the pin 49D of the second arm 49B fixed to the boss member 49 is inserted into the recess 56B of the link arm 56.

As shown in FIGS. 3 and 11, a pair of left and right operation arms 58 are swingably supported around a longitudinal axis P5 of a support frame disposed at the front of the body, and the front wheels 1 ( In the straight traveling position of the pitman arm 29), the rollers 58A of the right and left operation arms 58 are driven by the cam plate 32.
Is in contact with As shown in FIGS. 3, 8, 9, and 11, the right and left operation arms 58 and the link arm 56 of the right and left brake operation mechanisms 48 are connected by a spring 59 and a wire 60 for flexibility. Right and left operating arms 5
3 is provided with a stopper bolt 61 for stopping the return spring 6 in the posture of FIG.
2 is connected to the pin 56A of the link arm 56.

With the above structure, for example, the front wheels 1
When the steering operation is started to the left from the straight traveling position, the cam plate 32 fixed to the pitman arm 29 is moved to the left operating arm 5.
8, the wire 60 starts to be pulled and the wire 60 starts to be pulled. As a result, when the wire 60 is pulled to the left in FIG. 8 in the left brake operation mechanism 48, the boss member 49 is engaged by the engagement between the concave portion 56B of the link arm 56 and the pin 49D of the second arm 49B. Is rotated counterclockwise in FIG. 8, and the first arm 49 </ b> A of the boss member 49 starts operating the left side brake 45 toward the braking side. In this case, the front wheel 1 (pitman arm 2
As the steering angle to the left in 9) increases, the pulling operation amount of the wire 60 increases, and the braking force of the left side brake 45 increases in proportion to this.

As described above, the front wheel 1 (pitman arm 2)
9) The left side brake 45 is operated by the left steering operation.
When the steering angle to the left of the front wheel 1 (pitman arm 29) reaches the left set angle in a state in which is operated on the braking side, as described in FIG.
The cam arm 33 is swung to the left in FIG. 3 by the cam action of the pin A and the pin 33A, and the front wheel transmission 9 is operated in a speed increasing state in which the front wheel 1 is driven at a higher speed than the rear wheel 2. You. Accordingly, the body slightly turns left due to braking of the left rear wheel 2 by the left side brake 45 and a state in which the front wheel 1 is driven at a higher speed than the rear wheel 2 due to the increased speed of the front wheel transmission 9. Turn.

Next, when the turning is completed and the front wheel 1 (pitman arm 29) is operated to return to the straight traveling position, the amount of pulling operation of the wire 60 is reduced, and the left side brake 45 is proportionally increased. Braking force is weakening. When the left steering angle of the front wheel 1 (pitman arm 29) exceeds the left set angle and is returned to the straight traveling position, the cam arm 33 is returned to the position shown in FIG. The front wheel transmission 9 is operated in a standard state in which the front wheel 1 and the rear wheel 2 are driven at substantially the same speed. When the front wheel 1 (pitman arm 29) is operated to return to the straight traveling position,
The left side brake 45 is returned to the state of the braking force “0” and operated.

(5) Next, the front wheel 1 (pitman arm 2)
When the steering operation of 9) is performed, as described in the preceding section (4),
An operation state in which the side brake 45 on the turning center side is automatically operated to the braking side and an operation structure to a stopped state in which the side brake 45 is not operated to the braking side will be described. As shown in FIGS. 10 and 11, an operation plate 63 is swingably supported around a horizontal axis P6, and a first operation lever 43 is fixed to the operation plate 63. As shown in FIG. The first operation lever 43 is disposed below the seat 67. As shown in FIGS. 8, 9, 10, and 11, the link arm 56 of the right and left brake operation mechanisms 48 and the operation plate 63 are connected by a pair of wires 64. As shown in FIG. 10 and FIG.
A long hole 63 </ b> A is formed in the operation plate 63.
A and the balance arm 41 of the second operation lever 44 are connected by a wire 65.

The state shown in FIG. 10 is a state in which the first and second operating levers 43 and 44 are operated to the operating positions. As shown in FIG. The pin 49D of the second arm 49B enters the recess 56B, and the operation pin 35A of the operation shaft 35 is engaged with the shift fork 34 as shown in FIG. In this state, for example, when the front wheel 1 (pitman arm 29) is steered to the left, the left side brake 45 is operated to the braking side as described in the preceding items (3) and (4), and the front wheel transmission 9 is operated. It is operated from the standard state to the speed increasing state.

Next, when the first operation lever 43 is operated from the operation position to the stop position, the pair of wires 64 is pulled toward the operation plate 63, and the link arms 56 of the right and left brake operation mechanisms 48 in FIG. As shown by a two-dot chain line, the swinging operation is performed in the counterclockwise direction on the paper surface, so that the concave portion 56B of the link arm 56 is separated from the pin 49D of the second arm 49B to the right side of the paper surface. In conjunction with the operation of the first operation lever 43 to the stop position, the second operation lever 44 is operated from the operation position to the stop position by the wire 65, and the operation shaft 35 is slid to the right in FIG. , Operating pin 35 of operating shaft 35
A moves away from the shift fork 34.

In this state, even if the front wheel 1 (pitman arm 29) is steered to the left and the wire 60 is pulled to the left in FIG.
A merely moves leftward on the paper along the long hole 49C of the first arm 49A, the boss member 49 is not rotated counterclockwise on the paper, and the left side brake 45 is operated on the braking side. Never. Further, even if the front wheel 1 (pitman arm 29) is swung from the straight-ahead position by more than the right or left set angle, the operation shaft 35 only idles and the shift fork 34 does not slide, and the front wheel transmission 9 increases. It is left in the normal state without being operated in the fast state.

As described above, the first and second operation levers 4
When the first and second operating levers 43 are operated from the stop position to the operating position, the first operating lever 43 can be operated from the stop position to the operating position in a state where the third and fourth operating members are operated to the stop position. Due to the action of the long hole 63A of the operation plate 63, the second operation lever 44 is not operated to the operation position but remains at the stop position. As shown in FIG. 10, the first and second
In a state where the operation levers 43 and 44 are operated to the operation positions, the first operation of the operation plate 63 is performed by the action of the long hole 63A.
The operation lever 43 is left in the operating position and the second operation lever 4
4 can be operated from the operating position to the stop position.

As shown in FIGS. 1 and 10, a sub-transmission lever 66 for operating the sub-transmission 17 to the low-speed position L and the high-speed position H is disposed on the left side of the driver's seat 67. When traveling on the road at a relatively high speed, the sub-transmission lever 17 is operated to shift the speed of the sub-transmission device 17 to the high-speed position H.
6, the sub-transmission 17 is shifted to the low-speed position L.
As shown in FIG. 10, a long hole 63 formed in the operation plate 63 is provided.
B and the auxiliary transmission lever 66 are connected via a wire 68.

With the above configuration, when the sub-transmission lever 66 is operated from the low-speed position L to the high-speed position H while the first and second operation levers 43 and 44 are being operated to the operation positions as shown in FIG. The first operating lever 43 is operated from the operating position to the stop position by the wire 68 and the wire 6
5, the second operation lever 44 is operated from the operating position to the stop position.

As shown in FIG. 10, when the sub-transmission lever 66 is operated to the low speed position L, the first operation lever 43 is operated from the operation position to the stop position by the action of the long hole 63B of the operation plate 63. Can be the first
In conjunction with the operation of the operation lever 43 to the stop position, the second operation lever 44 is operated from the operation position to the stop position by the wire 65.

[Alternative Embodiment of the Invention] In the configuration shown in FIGS. 1 to 12, the front wheel transmission 9 is provided.
, The front wheel transmission 9 may not be provided. If the front wheel transmission 9 is not provided as shown in FIG. 13, the cam arm 33, the link rod 37, the second operation lever 44, the balance arm 41, and the wires 42, 6 shown in FIG.
5 is not required.

[0043]

According to the first aspect of the present invention, in a paddy field working vehicle provided with a side brake capable of independently braking the left and right rear wheels, it is possible to depress the side brake pedal on the turning center side when turning. In addition, the side brake on the turning center side is automatically operated to the braking side, so that the driver can easily perform the turning operation, and the operability of the paddy field work vehicle can be improved.

According to the first aspect of the present invention, when the speed of the traveling transmission is shifted to a relatively high speed traveling position on the road, the operating means for automatically operating the side brake on the turning center side to the braking side is automatically operated. By being configured to be operated in a stopped state, when turning while driving at high speed,
The side brake on the turning center side is automatically operated to the braking side, which makes it possible to avoid a situation in which the vehicle turns suddenly and the ride quality deteriorates, thereby improving the ride comfort of the paddy field work vehicle I was able to. In this case,
In response to the shifting operation of the transmission for traveling to the traveling position on the road, the artificial operation tool of the operating means is moved to the stop position, and the driver is informed that the operating means has been automatically operated to the stopped state. Therefore, the driver's erroneous operation based on the misunderstanding can be prevented beforehand.

According to a second aspect of the present invention, in a paddy field working vehicle provided with a side brake and a front wheel transmission capable of independently braking the left and right rear wheels, the turning brake pedal on the turning center side is not depressed during turning. Even so, the side brake on the turning center side is automatically operated to the braking side, and the front wheel transmission is automatically operated from the standard state to the speed increasing state, so that the driver can perform the turning operation easily. As a result, the operability of the paddy field working vehicle could be improved.

According to the second aspect of the present invention, the first operating means for automatically operating the side brake on the turning center side on the braking side by shifting the speed of the traveling transmission to a relatively high speed traveling position on the road, And the second operating means for automatically operating the front wheel transmission from the standard state to the speed increasing state is configured to be automatically operated to the stop state, so that when turning at a high speed, The state in which the side brake on the turning center side is automatically operated to the braking side, and the front wheel transmission is automatically operated from the standard state to the speed increasing state, resulting in a sudden turning state and a decrease in riding comfort. It was possible to improve the riding comfort of the paddy field working vehicle. In this case, the first and second artificial operating tools of the first and second operating means move to the stop position in conjunction with the shifting operation of the traveling transmission to the road traveling position, and the first and second operating means move to the stop position. Since the driver can recognize that the second operation means has been automatically operated in the stop state, the driver's erroneous operation based on misunderstanding can be prevented beforehand.

According to the features of claim 3, claim 1 or 2
"Effects of the Invention" of Claim 1 or 2 as in the case of
In addition to this “effect of the invention”, the following “effect of the invention” is provided. According to the third aspect of the present invention, the braking force of the side brake on the turning center side is set to be strong depending on the steering angle of the front wheel from the straight traveling position, so that the turning wheel on the turning center side. In this way, it is possible to reduce the roughness of the rice field caused by the rear wheel on the turning center side, thereby improving the running performance of the paddy field working vehicle.

According to the feature of claim 4, claim 2 or 3
The effect of the invention according to claim 2 or 3 as in the case of
In addition to this “effect of the invention”, the following “effect of the invention” is provided. According to the fourth aspect of the present invention, the operating member located at the end of the linking mechanism is separated from the operated portion while the linking mechanism for mechanically linking the front wheel and the operating member is linked. Since the second operating means can be operated in the stopped state, it is not necessary to adopt a complicated structure in which a part of the linking mechanism is separated to obtain the stopped state of the second operating means. Become
This is advantageous in terms of simplifying the structure.

[Brief description of the drawings]

FIG. 1 is an overall side view of a riding rice transplanter.

FIG. 2 is a side view of the vicinity of a front wheel transmission and a pitman arm.

FIG. 3 is a plan view of the vicinity of a front wheel transmission and a pitman arm.

FIG. 4 is a cross-sectional plan view near the front wheel transmission.

FIG. 5 is a side view of the vicinity of a front wheel transmission and a second operation lever.

FIG. 6 is a longitudinal sectional front view near a pitman arm.

FIG. 7 is a longitudinal rear view near the front wheel transmission.

FIG. 8 is a side view of a brake operation mechanism.

FIG. 9 is a rear view of the brake operation mechanism.

FIG. 10 is a diagram showing a linked state of first and second operation levers and a sub-transmission lever.

FIG. 11 is a diagram showing a linked state of a pitman arm, a front wheel transmission, and a side brake.

FIG. 12 is a longitudinal sectional front view of the vicinity of a pipe frame of a rear axle case.

FIG. 13 is a view showing a linked state of a pitman arm and a side brake according to another embodiment of the invention.

[Explanation of symbols]

 Reference Signs List 1 front wheel 2 rear wheel 9 front wheel transmission 17 traveling transmission 33, 36, 37 linkage mechanism 34 operated part 35 operating member 43 artificial operation tool, first artificial operation tool 44 second artificial operation tool 45 side brake 65, 68 Checking means L Work traveling position H Road traveling position

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kenji Fujii 64 Ishizu-Kitacho, Sakai City, Osaka Prefecture Inside Kubota Sakai Plant (72) Inventor Masakazu Furuichi 64 Ishizu-Kitacho, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. Inside

Claims (4)

[Claims] 1. A vehicle comprising: a pair of left and right front wheels that can be steered to the left and right; a pair of left and right rear wheels; and a side brake that can independently brake the left and right rear wheels, wherein the front wheels move right or left from a straight ahead position. Operating means capable of operating the side brake on the turning center side to the braking side when the steering operation is performed, and an artificial operating tool capable of artificially operating the operating means in an activated state and a stopped state. Paddy field work vehicle provided with a check means for operating the artificial operation tool to a stop position in conjunction with the speed change operation when the transmission for the vehicle is shifted from the work travel position to the road travel position. 2. A pair of left and right front wheels steerable left and right, a pair of left and right rear wheels, a side brake capable of independently braking the left and right rear wheels, and a front wheel and a rear wheel having substantially the same speed. A front wheel transmission that is operable in a standard state to be driven and a speed-up state in which the front wheels are driven at a higher speed than the rear wheels. A first operating means capable of operating the side brake on the braking side, and a first artificial operating tool capable of operating the first operating means artificially in an operating state and a stopped state, wherein the front wheel is moved rightward from the straight-ahead position. Or a second operating means for operating the front wheel transmission from a standard state to a speed increasing state when the steering operation is performed to the left; and a second artificial means capable of artificially operating the second operating means in an operating state and a stopped state. Operating gear, and the traveling transmission is in the working traveling position. When speed change operation Luo road position, paddy work vehicle that is provided with a restraining means for operating the stop position the first and second manual control device in conjunction with the shift operation. 3. The larger the steering angle of the front wheel from the straight traveling position, the stronger the braking force of the side brake on the turning center side, and the smaller the steering angle of the front wheel from the straight traveling position, the more the steering angle on the turning center side. The paddy field working vehicle according to claim 1 or 2, wherein the braking force of the side brake is configured to be weak. 4. An operating member for operating the front wheel transmission from a standard state to a speed increasing state by engaging the operated part of the front wheel transmission to move the operated part, and And a linkage mechanism for mechanically linking the operating member to constitute the second operating means. By operating the operating member away from the operated part, the stopped state of the second operating means is displayed. To put out
The paddy field working vehicle according to claim 2, wherein the second artificial operation tool is configured.